CVE-2016-2824 in Firefox
Summary
by MITRE
The TSymbolTableLevel class in ANGLE, as used in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2 on Windows, allows remote attackers to cause a denial of service (out-of-bounds write and application crash) or possibly have unspecified other impact by triggering use of a WebGL shader that writes to an array.
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Analysis
by VulDB Data Team • 10/23/2024
The vulnerability identified as CVE-2016-2824 resides within the TSymbolTableLevel class implementation in ANGLE graphics library, which serves as a critical component in Mozilla Firefox's WebGL rendering pipeline on Windows platforms. This flaw represents a classic buffer overflow condition that manifests when the application processes WebGL shader code containing array write operations. The vulnerability specifically affects Firefox versions prior to 47.0 and Firefox ESR 45.x versions prior to 45.2, indicating a prolonged period during which this security gap remained unaddressed in widely deployed browser versions.
The technical exploitation of this vulnerability occurs through the manipulation of WebGL shader programs that attempt to write beyond the bounds of allocated memory arrays. When the TSymbolTableLevel class processes such malformed shader code, it fails to properly validate array access boundaries, leading to out-of-bounds memory writes that can corrupt adjacent memory regions. This memory corruption directly translates into application instability, resulting in denial of service conditions through application crashes or, in more severe cases, potentially enabling arbitrary code execution depending on the specific memory corruption patterns. The vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions, and more broadly aligns with CWE-787, concerning out-of-bounds write operations.
The operational impact of this vulnerability extends beyond simple application instability to encompass potential security risks for end users. Remote attackers can leverage this flaw by crafting malicious WebGL content that, when rendered by an affected browser, triggers the exploitable condition. This creates a significant attack surface since WebGL content can be embedded within web pages, making the vulnerability accessible through standard web browsing activities. The risk is particularly elevated in environments where users browse untrusted websites, as the vulnerability can be exploited without any user interaction beyond visiting compromised web pages. The potential for unspecified other impacts suggests that under certain conditions, this vulnerability might provide attackers with opportunities for privilege escalation or information disclosure, though the exact scope of these additional risks requires further analysis.
Mitigation strategies for CVE-2016-2824 primarily focus on immediate version upgrades to patched Firefox releases, which contain the necessary code modifications to properly validate WebGL shader array operations. Security administrators should prioritize updating affected systems and implementing browser security policies that restrict WebGL functionality where possible. The fix implemented by Mozilla likely involves enhanced bounds checking within the TSymbolTableLevel class and improved validation of WebGL shader program compilation processes. Additionally, organizations should consider implementing network-level protections such as web application firewalls and content filtering solutions that can detect and block suspicious WebGL content. This vulnerability underscores the importance of maintaining up-to-date security patches and highlights the critical nature of graphics library security in modern web browsers, as demonstrated by the ATT&CK framework's categorization of such vulnerabilities under the software exploitation domain, specifically targeting browser rendering engines and graphics processing components.