CVE-2016-5278 in Firefox
Summary
by MITRE
Heap-based buffer overflow in the nsBMPEncoder::AddImageFrame function in Mozilla Firefox before 49.0 and Firefox ESR 45.x before 45.4 allows remote attackers to execute arbitrary code via a crafted image data that is mishandled during the encoding of an image frame to an image.
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Analysis
by VulDB Data Team • 09/20/2022
The vulnerability identified as CVE-2016-5278 represents a critical heap-based buffer overflow affecting Mozilla Firefox versions prior to 49.0 and Firefox ESR 45.x versions prior to 45.4. This flaw resides within the nsBMPEncoder::AddImageFrame function, which handles the encoding process of image frames into bitmap format. The vulnerability stems from inadequate input validation and memory management when processing crafted image data, creating an exploitable condition that can be leveraged by remote attackers to execute arbitrary code on affected systems. The issue demonstrates the classic characteristics of a heap overflow where maliciously constructed data exceeds the allocated buffer boundaries, potentially corrupting adjacent memory regions and enabling code execution.
The technical implementation of this vulnerability involves the manipulation of image data structures during the bitmap encoding process, specifically within the nsBMPEncoder component. When Firefox processes an image frame through the AddImageFrame function, it fails to properly validate the size and structure of incoming image data, leading to a situation where buffer boundaries are exceeded. This type of vulnerability falls under CWE-121, which categorizes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution. The flaw occurs during the handling of image frame data where the system allocates memory based on expected data sizes but receives unexpectedly large or malformed input, causing memory corruption that can be exploited to overwrite critical program execution structures.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data breach scenarios. Remote attackers can craft malicious image files that, when processed by Firefox, trigger the buffer overflow condition and subsequently execute attacker-controlled code with the privileges of the Firefox process. This creates a significant threat vector for phishing attacks, drive-by downloads, and other web-based exploitation techniques. The vulnerability's remote nature means that users can be compromised simply by viewing malicious content in their browsers, making it particularly dangerous for widespread deployment. Security researchers have noted that exploitation often involves crafting specific image data patterns that trigger the memory corruption, with successful exploitation typically resulting in complete browser compromise and potential system access.
Mitigation strategies for CVE-2016-5278 primarily focus on immediate version updates to patched Firefox releases, which address the underlying buffer overflow through proper input validation and memory management. Organizations should prioritize deployment of Firefox 49.0 or later versions for regular releases and Firefox ESR 45.4 or later for extended support releases. Additional protective measures include implementing web content filtering solutions, disabling unnecessary image processing capabilities in browsers, and employing sandboxing technologies to limit the potential impact of successful exploitation attempts. Network security controls such as intrusion prevention systems can be configured to detect and block known malicious image file patterns associated with this vulnerability. The remediation process should also include comprehensive security awareness training for users to recognize potentially malicious web content and avoid visiting compromised websites that might leverage this vulnerability for initial access.