CVE-2016-5252 in Firefox
Summary
by MITRE
Stack-based buffer underflow in the mozilla::gfx::BasePoint4d function in Mozilla Firefox before 48.0 and Firefox ESR 45.x before 45.3 allows remote attackers to execute arbitrary code via crafted two-dimensional graphics data that is mishandled during clipping-region calculations.
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Analysis
by VulDB Data Team • 09/09/2022
The vulnerability identified as CVE-2016-5252 represents a critical stack-based buffer underflow affecting Mozilla Firefox versions prior to 48.0 and Firefox ESR 45.x versions prior to 45.3. This flaw resides within the mozilla::gfx::BasePoint4d function which processes two-dimensional graphics data during clipping-region calculations. The vulnerability stems from improper bounds checking during the handling of graphical elements that are processed through the graphics rendering pipeline. When maliciously crafted two-dimensional graphics data is encountered during normal browser operation, the function fails to validate the size of data structures before performing memory operations, leading to a buffer underflow condition that can be exploited by remote attackers.
The technical implementation of this vulnerability involves the manipulation of graphics data structures that are processed through Firefox's rendering engine. During clipping-region calculations, the BasePoint4d function receives input data that should contain specific geometric coordinates for graphics elements. However, when this data contains unexpected values or malformed structures, the function performs memory operations without adequate bounds validation, causing data to be written beyond the allocated stack buffer boundaries. This condition creates a predictable memory corruption scenario that can be leveraged to overwrite adjacent memory locations including return addresses and function pointers, enabling arbitrary code execution. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows occurring in stack memory regions where insufficient bounds checking allows data to overflow into adjacent memory areas.
The operational impact of CVE-2016-5252 extends beyond typical browser exploitation scenarios due to the nature of graphics processing in web environments. Attackers can craft malicious web pages containing specially formatted graphics data that, when rendered by Firefox, triggers the vulnerable code path. This allows for remote code execution without requiring user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns or drive-by download scenarios. The vulnerability affects both regular Firefox releases and the extended support release (ESR) versions, meaning organizations using legacy browser versions remain at risk. The attack surface is broad as graphics rendering is fundamental to web browsing, and the exploitation can occur through various vector including embedded images, canvas elements, SVG graphics, or other rich media content that triggers the problematic code path in the graphics subsystem.
Mitigation strategies for this vulnerability primarily focus on immediate browser updates to versions that contain the patched implementation of the BasePoint4d function. Mozilla released Firefox 48.0 and Firefox ESR 45.3 with fixes that include proper bounds checking and memory validation during graphics data processing. Organizations should prioritize patch management to ensure all affected browsers are updated promptly, as the vulnerability can be exploited remotely without user interaction. Additional defensive measures include implementing web application firewalls that can detect and block suspicious graphics data patterns, employing content security policies that limit the execution of potentially malicious embedded content, and monitoring network traffic for indicators of exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution through browser exploitation, specifically covering the T1203 Suspicious Process Creation and T1059 Command and Scripting Interpreter categories where attackers leverage browser vulnerabilities to establish persistent access to target systems. The vulnerability also relates to T1190 Exploit Public-Facing Application as it represents a remote exploit opportunity within a widely used public application.