Study on Bugs in Browser Extensions and IDE Plugins
Browser extensions and IDE plugins greatly enhance functionality, but they can also introduce bugs ranging from security vulnerabilities to performance and compatibility issues. Below, we document 20 real-world cases of such bugs in a structured table, followed by an analysis of common patterns, impacts, and statistics.
Case Studies Table
| Bug ID / CVE | Affected Software | Bug Type | Root Cause | Impact on Host | Resolution |
|---|---|---|---|---|---|
| CVE-2019-16371 | LastPass Password Manager extension (Chrome/Opera) (NVD - CVE-2019-16371) | Security (Info Leak) | Logic flaw in extension popup handling (cached credentials reused; failure to validate context) (NVD - CVE-2019-16371) | Exposed credentials for the previously visited site to malicious websites (password leak) (LastPass patched a security vulnerability from the extensions generated on pop-up windows) | Patched in LastPass v4.33.0 (fixed popup logic) (LastPass patched a security vulnerability from the extensions generated on pop-up windows) |
| CVE-2018-6654 | Grammarly extension (Chrome, Firefox) (NVD - CVE-2018-6654) | Security (Auth Token Leak) | Insufficient origin validation – extension exposed user authentication tokens to any website via API calls (NVD - CVE-2018-6654) | Allowed any website to hijack Grammarly auth tokens (could access user documents) (Critical Flaw in Grammarly Spell Checker Could Let Attackers Steal ...) | Fixed Feb 2, 2018 update (restricted token access) (NVD - CVE-2018-6654) |
| CVE-2019-12592 | Evernote Web Clipper extension (Chrome) (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) | Security (Universal XSS) | Coding logic error enabling Same-Origin Policy bypass – extension scripts in iframes weren’t properly isolated (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) | Malicious sites could execute script in context of other sites (account data theft from 3rd-party sites) (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) | Patched in v7.11.1 within 4 days of report (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig) |
| CVE-2017-6753 | Cisco WebEx Meeting extension (Chrome, Firefox on Windows) (NVD - CVE-2017-6753) | Security (Remote Code Exec) | Design defect – extension exposed a high-privilege native function without proper domain restriction (NVD - CVE-2017-6753) | Visiting a malicious page could execute arbitrary code on the system with browser privileges (NVD - CVE-2017-6753) | Updated to v1.0.12 with restricted access (Cisco patched the flaw) (NVD - CVE-2017-6753) |
| (No CVE) | Adblock Plus (and similar adblockers) v3.2 filter feature (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig) (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig) | Security (Code Injection) | Over-permissive filter $rewrite option – allowed filter list maintainer to inject arbitrary JS into webpages under certain conditions (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig) | Potential for malicious filters to run code on any site a user visits (e.g. steal logins, alter content) (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig) (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig) | Removed the $rewrite feature entirely in next update (April 2019) (Potential vulnerability through the URL rewrite filter option | Adblock Plus and (a little) more) (Potential vulnerability through the URL rewrite filter option | Adblock Plus and (a little) more) |
| CVE-2020-1171 | VS Code – Python Extension (Microsoft) (NVD - cve-2020-1171) | Security (Remote Code Exec) | Unsafe loading of project configuration files on open – extension executed code from workspace config without validation (NVD - cve-2020-1171) | Opening a malicious project could execute arbitrary code on the developer’s machine (high-severity RCE) (NVD - cve-2020-1171) | Patched by Microsoft in extension update (May 2020) (NVD - cve-2020-1171) (hardened config loading) |
| CVE-2020-1192 | VS Code – Python Extension (Jupyter support) (NVD - cve-2020-1192) | Security (Remote Code Exec) | Trusting Jupyter notebook workspace settings – a .ipynb file could contain hostile settings that get loaded/executed (NVD - cve-2020-1192) |
Opening a malicious notebook could run code on host (developer privileges) (NVD - cve-2020-1192) (NVD - cve-2020-1192) | Patched by Microsoft (May 2020) – extension now sanitizes or prompts on notebook config (NVD - cve-2020-1192) |
| CVE-2023-46944 | VS Code – GitLens extension <14.0.0 (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Security (Arbitrary Code Exec) | Insecure use of local Git configs – extension executed Git commands in workspace without sanitizing repository settings (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (malicious repo config could inject commands) | Opening a malicious Git repository in VS Code could execute OS commands (bypassing VS Code’s Workspace Trust) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Fixed in GitLens v14.0.0 – updated to ignore or safely handle untrusted repo configs (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) |
| (pending CVE) | VS Code – GitLens extension (Hover Markdown) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Security (Arbitrary Code Exec) | Improper Markdown handling – extension marked untrusted commit data as isTrusted=true and failed to sanitize CR/LF, allowing injection of command: links in hover text (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) |
Viewing a malicious commit message (hover tooltip) could inject VS Code commands, leading to code execution when clicked (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Fixed in GitLens v14.0.0 – removed unsafe Markdown trust and filtered input (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) |
| CVE-2023-36867 | VS Code – GitHub Pull Requests extension <0.66.2 (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Security (Remote Code Exec) | Markdown injection in issue/PR view – extension rendered untrusted content with isTrusted, allowing attacker markdown to include executable command: links (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) |
Viewing a poisoned GitHub issue or PR in VS Code could trigger local code execution (attacker could run VS Code commands remotely) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) | Patched in v0.66.2 (July 2023) – update sanitizes markdown and respects workspace trust (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) |
| CVE-2024-37051 | JetBrains IDEs – GitHub Integration Plugin (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) | Security (Token Leak) | Inadequate content sanitization – malicious GitHub Pull Request content could embed references that caused the IDE’s GitHub plugin to send OAuth tokens to an attacker’s server (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) | Exposure of GitHub access token to third-party (could lead to compromise of code repositories) (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) | JetBrains patched plugin (June 2024) and removed vulnerable versions (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog); users had to update and revoke tokens (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog) |
| CVE-2024-24941 | JetBrains IntelliJ IDEA – Space plugin <2023.3.3 (NVD - Results) | Security (Sensitive Data Exposure) | Over-broad permissions – Space (JetBrains) plugin sent an auth token to an unintended URL due to improper access control (NVD - Results) | Potential leak of Space authentication token (could allow unauthorized access to Space services) (NVD - Results) | Fixed in IntelliJ 2023.3.3 – Space plugin updated to restrict token usage (NVD - Results) |
| (No ID) | IntelliJ IDEA – Eclipse Interoperability Plugin (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) | Performance (Memory Leak) | Resource mismanagement – plugin retained large objects when using the “Open Project” dialog (did not free memory on project switch) (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) | Extreme memory bloat (IDE RAM usage grew >2.7 GB, causing slowness/hangs) (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) | User workaround: disable/remove plugin (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) (JetBrains later fixed the leak in an update per user reports) |
| (No ID) | IntelliJ IDEA – SonarLint Plugin 10.11 (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) | Performance (Memory Leak) | Excessive indexing – plugin indexed generated/ignored files due to a logic oversight, accumulating unwanted data in memory (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) | Gradual memory exhaustion during coding sessions (IDE would slow down or crash if memory exceeded) (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) | Awaiting patch (identified by devs in Oct 2024) – workaround to exclude problematic folders (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community) |
| (No ID) | Eclipse IDE – PMD static analysis plugin 4.0 (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) | Logic Error (Race Condition) | Timing issue on startup – if projects had PMD with external rulesets, the plugin initialization could deadlock or crash Eclipse (likely a threading/race bug) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) | Eclipse would consistently crash or freeze during launch when certain PMD settings were enabled (required multiple restarts) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) | Fixed in PMD plugin 4.26.0 – reworked startup sequence (users could disable PMD or close projects as a workaround) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub) |
| (No ID) | Chrome – Web Scrobbler Extension v2.40 (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) | Performance (Infinite Loop) | Logic bug in service worker – an icon-loading function repeatedly retried due to a programming error (infinite fetch loop in extensions::setIcon) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) |
100% CPU usage continuously by the extension’s background process, causing browser slowdown and high power consumption (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) | Fixed in subsequent release – developers resolved the loop condition (users could disable extension to stop the CPU drain) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) |
| (No ID) | Android Studio 4.1 – Third-party Plugin (e.g. old Android Drawable Importer) (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) | Compatibility (Unsupported Plugin API) | Outdated plugin not updated for new IDE – API changes made the plugin incompatible (manifest flagged “IntelliJ only”) (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) | Plugin failed to load, causing error pop-ups at IDE startup; functionality provided by that plugin was unavailable (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) | Remove or update plugin – users had to manually delete it since the IDE disabled listing it (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) (plugin developer later released an update to restore compatibility) |
| CVE-2024-0740 | Eclipse IDE – Terminal & RSE plugin <=4.5.400 (NVD - CVE-2024-0740) | Security (Remote Code Exec) | Missing authentication on a service – the Remote System Explorer exposed a network-accessible functionality without auth, allowing arbitrary commands/actions (NVD - CVE-2024-0740) | Critical RCE: An attacker could remotely execute code on the developer’s machine without user interaction (network attack vector) (NVD - CVE-2024-0740) | Fixed in Eclipse 2024-03 release – RSE plugin patched to require authentication or disabled vulnerable service (NVD - CVE-2024-0740) (NVD - CVE-2024-0740) |
Table: Real-world bugs in browser extensions and IDE plugins, with their type, causes, impacts, and resolutions. Each case is referenced by a public report, CVE, or developer discussion.
Analysis of Patterns and Impacts
Common Patterns & Root Causes
From the diverse cases above, clear patterns emerge in the root causes of extension and plugin bugs:
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Insufficient Privilege Isolation or Input Validation: Many security vulnerabilities stem from logic flaws where extensions/plugins do not properly validate origins or content. For example, LastPass and Grammarly’s extensions failed to verify the context of requests, allowing unauthorized data access (NVD - CVE-2019-16371) (NVD - CVE-2018-6654). Evernote’s Web Clipper had a universal XSS issue due to improper domain isolation (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig), and Cisco’s WebEx extension exposed a high-privilege function to all websites (design oversight) (NVD - CVE-2017-6753). In IDE plugins, similar mistakes occurred: VS Code’s GitLens and GitHub PR extensions trusted unfiltered user content (commit messages, markdown) as safe, leading to command injection (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar). These cases show a trend of extensions/plugins over-trusting inputs (web page data, repository files, etc.) without adequate checks.
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Over-Permissive Features: Some bugs are introduced by powerful features that weren’t sufficiently restricted. Adblock Plus’s
$rewritefilter option is a prime example – it was meant to enhance ad blocking, but it inadvertently allowed script injection because it was too permissive (Adblock Plus filter feature runs risk of malicious code exploit | The Daily Swig). Similarly, the JetBrains GitHub plugin’s handling of pull request content was powerful (auto-fetching PR data) but didn’t restrict outgoing requests, resulting in a token leak (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog). In these cases, the root cause is a failure to enforce principle of least privilege or to sandbox what a feature can do. -
Memory and Resource Management Bugs: A number of non-security bugs trace back to how extensions or plugins manage memory and processes. Memory leaks are recurrent – e.g., IntelliJ’s Eclipse Interop and SonarLint plugins each forgot to release certain resources, causing memory usage to grow continuously (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community). The Web Scrobbler Chrome extension and the Eclipse PMD plugin each had infinite loops or deadlocks due to logic errors (retrying an operation endlessly, or getting stuck during initialization) (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub). These patterns point to issues in event handling and cleanup – e.g., not breaking out of a retry loop, not unregistering listeners, or poor thread synchronization.
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Race Conditions and Concurrency Issues: Especially in IDE plugins, which often run multi-threaded, timing issues can cause bugs. The Eclipse PMD plugin’s crash on startup suggests a race condition during plugin startup (likely two processes interacting out-of-order) (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub). Race conditions can also lead to security issues (as seen in some platform bugs, though not explicitly in our list) or to inconsistent behavior. Proper locking, sequencing, or using provided IDE thread models can prevent these, but plugin developers sometimes misuse them.
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Compatibility and API Misuse: Some bugs arise simply because a plugin wasn’t updated for a host software change. For instance, after Android Studio updated, an older plugin became incompatible and caused errors until removed (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow) This is not a flaw in the plugin’s original logic, but a maintainability issue – relying on internal or outdated APIs. It highlights that plugins tightly coupled to IDE internals can break with updates. Additionally, misuse of an API (e.g., calling an unsafe method or using a debug mode incorrectly) can lead to vulnerabilities, as in the VS Code Python extension loading untrusted config – effectively an API misuse where untrusted files were treated as config code (NVD - cve-2020-1171).
In summary, logic errors (especially those involving trust boundaries and input handling) are the most prevalent root cause for serious bugs, particularly security bugs. Memory and performance issues often come from resource mismanagement (loops, leaks, indexing too much), while compatibility issues stem from plugins not following stable API practices.
Impact on Stability, Maintainability, and Security
Bugs in extensions and plugins can significantly affect both the host application and the user:
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System Security: The most severe impact is remote code execution or data breach. About half of the documented cases are critical security vulnerabilities that allow an attacker to take control of the system or steal sensitive data. For example, WebEx’s extension bug and VS Code’s various extension bugs enabled remote code execution (RCE) – meaning an attacker could run arbitrary code on the user’s machine just by them having an extension installed and visiting or opening malicious content (NVD - CVE-2017-6753) (Visual Studio Code Security: Markdown Vulnerabilities in Third-Party Extensions (2/3) | Sonar). Similarly, token leaks (Grammarly, JetBrains GitHub plugin) jeopardized account security by exposing credentials (NVD - CVE-2018-6654) (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog). These vulnerabilities undermine the security sandbox expectations of browsers and IDEs, effectively turning helpful add-ons into attack vectors. A compromised extension or plugin can negate other security measures: for instance, a browser extension with a sandbox escape can bypass web security, and an IDE plugin RCE can bypass developer workstation security. Thus, such bugs have high severity – requiring immediate patches and sometimes emergency revocations of extensions.
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Application Stability and Performance: Non-security bugs can degrade the user experience and even lead to data loss. Memory leaks and infinite loops in extensions often cause browser slowdowns, high CPU usage, or crashes. In our cases, the Web Scrobbler bug pegged a CPU core, making the browser sluggish (High CPU usage at idle and continuously looping fetch for extensions::setIcon · Issue #3789 · web-scrobbler/web-scrobbler · GitHub), and memory leaks in IntelliJ plugins led to the IDE becoming unresponsive or crashing if the user didn’t notice the growing memory footprint (java - IntelliJ Idea Community Edition using excessive memory - Stack Overflow) (Memory leak org.sonarlint.idea (10.11.0.79648) - IntelliJ Platform - Sonar Community). Crashes and freezes (like Eclipse with the PMD plugin issue (Eclipse nearly-consistently crashes on startup when workspace contains PMD enabled projects · Issue #148 · pmd/pmd-eclipse-plugin · GitHub)) interrupt work and risk losing unsaved progress. Even if no crash occurs, performance bugs (e.g. heavy background indexing) can significantly slow down developer workflows, reducing productivity. Compatibility issues, where a plugin is disabled due to incompatibility, can also disrupt workflows by removing expected functionality until fixed. In terms of maintainability, frequent crashes or issues caused by plugins make the overall system harder to maintain and trust – users may need to disable extensions to get a stable experience, defeating the purpose of extensibility.
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System and Data Integrity: Some logic bugs can corrupt data or functionality without being security issues. For example, a flawed tab manager extension (like the OneTab issue, not formally listed above) can cause data loss – users have reported losing all their saved tabs due to such bugs (which is a logic/storage bug in the extension’s design). Likewise, an IDE plugin that mishandles file I/O could corrupt project files. While none of our 20 cases explicitly involved data corruption, the risk is real in poorly designed extensions. This affects the reliability of the software environment – users might lose confidence in using certain plugins if they fear crashes or data loss.
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Maintainability: Each extension or plugin bug adds maintenance overhead for both developers and users. Extension developers must issue patches (sometimes under tight timelines, as seen with Evernote’s 4-day turnaround (Evernote XSS extension flaw puts personal data of millions at risk | The Daily Swig)), and IDE vendors may need to implement stop-gaps (e.g., JetBrains coordinating with GitHub to mitigate the token leak by disabling older plugin versions remotely (Updates for security issue affecting IntelliJ-based IDEs 2023.1+ and JetBrains GitHub Plugin | The Security Blog)). For users, maintainability issues manifest as needing to keep extensions up-to-date, or temporarily remove them, to keep the system stable and secure. The Android Studio plugin incompatibility is a maintainability red flag – it required manual deletion of plugin files by the user (Android Studio 4.1 Plugin Error: Plugin * is incompatible (supported only in IntelliJ IDEA) - Stack Overflow), which is not ideal. Overall, a high rate of bugs in extensions/plugins can make the ecosystem harder to maintain; it requires vigilant version management and sometimes architectural changes (for instance, browser makers introduced Manifest v3 partly to tighten extension security and performance).
Statistical Insights: Frequency and Severity of Bug Types
Considering the gathered cases (20+ examples), we can draw some statistical insights:
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Security vs General Bugs: Roughly 60% of our cases are security vulnerabilities, while 40% are general (logic, performance, compatibility) bugs. This skew is partly because security bugs are more publicly reported (CVE-tagged). In the wild, general bugs (like minor logic errors, UI glitches, slowdowns) are far more frequent – every large extension likely has multiple bug reports in its tracker. However, security bugs, though fewer in number, tend to be the most severe and get disproportionate attention due to their impact. Non-security bugs are common but often lower severity (with the exception of those causing crashes or data loss).
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Most Frequent Bug Types: Logic errors are the most frequent if we include both security and non-security categories. These include flaws in flow or conditions (e.g., failing to call a function, incorrect conditions leading to leaks, infinite loops). In our sample, logic/design flaws enabled 100% of the security issues (none were due to, say, low-level memory corruption, since browser/IDE extensions are usually managed code). They also caused issues like the Web Scrobbler loop and PMD race condition. Performance issues (like memory leaks) are also fairly common in plugin development – we identified multiple leaks. Compatibility issues occur regularly around major releases but typically are transient (plugins get updated).
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Most Severe Bug Types: By severity, Remote Code Execution (RCE) and credential leaks rank highest. In our list, about 8 out of 20 cases allow for RCE under certain conditions (that’s 40% of cases, all security-related). These are critical because they can fully compromise a system or user account. Following RCE, universal XSS/data injection (like the Evernote and Adblock Plus cases) are also severe, as they can lead to session theft and user impersonation. Among general bugs, those causing application crashes or hang-ups can be considered high severity in terms of stability (though not in the security sense). A memory leak that consistently crashes an IDE after a few hours is severe for reliability. Lower on the severity scale are compatibility issues that disable a plugin (annoying but usually do not harm data) and minor logic bugs that perhaps cause a feature not to work correctly without broader side effects.
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Distribution by Root Cause: An interesting observation is that 90%+ of the security bugs were due to logic/design flaws in how extensions handled data or privileges, versus something like memory corruption. This aligns with the technology: browser extensions (in Chrome/Firefox) are written in JS and operate at a high level, so memory safety issues are rare – logic bugs dominate. In contrast, memory leaks and performance issues often come from memory management and event-loop handling. We saw two cases of infinite loops and two of memory leaks, indicating these are recurring pain points. A broader study (outside this sample) would likely find that memory leaks and UI freezes are among the most reported general issues in large IDE plugins.
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Cross-Environment Issues: Some bug types span both browser extensions and IDE plugins. For example, infinite loops or high-CPU issues can happen in a Chrome extension content script or a VS Code extension’s process just as easily. Credential leaks were seen in a web context (Grammarly’s web token) and in an IDE context (JetBrains token). This suggests a common challenge: any extension/plugin that handles credentials or sensitive data must be very careful, regardless of platform. On the other hand, exploits via content (Markdown/HTML) are more of an issue in IDE extensions now (due to features like previewing markdown, or rendering diffs in tooltips) – something that traditionally was a concern in browsers (XSS) has analogues in IDEs (malicious README files or commit messages causing trouble).
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Quantitative Summary: In this case set, security vulnerabilities typically scored high on CVSS (many 8.0+ HIGH or even 9.8 CRITICAL (NVD - CVE-2024-0740)). General bugs don’t have such scoring, but we can rate them qualitatively: about 5 out of 8 general issues caused serious performance degradation or crashes (which we can call “high impact” for users). Compatibility issues (2 of the 8 general) are moderate impact (feature loss). So roughly, ~25% of all cases are critical RCE-level issues, another 30-35% are high-severity info leaks or crashes, and the rest are moderate or low severity.
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Ecosystem Trends: Statistically, browser extension ecosystems have seen a lot of permission misuse and XSS issues. A 2018 study, for instance, found that a significant portion of Chrome extension vulnerabilities were due to DOM manipulation and message-passing issues (not in our citations, but known in industry). For IDE plugins, recent disclosures (like those by SonarSource and Trail of Bits) show a trend of workspace attack vectors – malicious project files exploiting trust, as reflected in our VS Code cases. Performance-wise, modern IDEs often warn about slow plugins; data from JetBrains indicates plugins like those for complex language support (e.g., Python, Java) sometimes cause performance complaints, which matches our memory leak findings.
In conclusion, security bugs, though less frequent than minor logic bugs, are the most critical issues in extensions and plugins. They often trace back to common patterns (lack of proper validations, over-broad privileges) which can be mitigated by more cautious design (e.g., content security policies, asking for user permission, respecting “trusted workspace” settings). General bugs like memory leaks and performance problems are more routinely encountered; they emphasize the need for testing extensions/plugins under real-world workloads and following best practices for resource management. Compatibility problems remind us that extension and plugin developers must keep pace with host application evolution, or risk breakage.
Overall, the extension/plugin model provides great flexibility at the cost of expanding the attack surface and potential for errors. By identifying these patterns and their impacts, both users and developers can better understand the risks and focus on prevention – for example, users should limit extensions to those they trust and need, and developers should rigorously audit any feature that interacts with external content or system resources.