CVE-2017-5465 in Firefox
Summary
by MITRE
An out-of-bounds read while processing SVG content in "ConvolvePixel". This results in a crash and also allows for otherwise inaccessible memory being copied into SVG graphic content, which could then displayed. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/26/2025
The vulnerability identified as CVE-2017-5465 represents a critical out-of-bounds read condition that occurs during the processing of Scalable Vector Graphics (SVG) content within the ConvolvePixel function. This flaw exists in Mozilla's rendering engine and specifically impacts the handling of convolution operations that are commonly used in SVG filters and effects. The issue stems from insufficient bounds checking when processing pixel data during image convolution operations, creating a scenario where the application attempts to read memory locations beyond the allocated buffer boundaries. This fundamental memory safety issue affects multiple Mozilla products including Thunderbird, Firefox Extended Support Release (ESR) versions, and standard Firefox releases, demonstrating the widespread nature of the vulnerability across the Mozilla ecosystem.
The technical execution of this vulnerability involves the ConvolvePixel function encountering malformed SVG content that triggers an out-of-bounds memory read operation. When processing convolution kernels, the function fails to properly validate input parameters and buffer sizes, allowing attackers to craft malicious SVG files that cause the application to access memory regions that should remain protected. This memory access pattern can result in application crashes due to segmentation faults or access violations, but more critically, it enables information disclosure by allowing arbitrary memory contents to be copied into the SVG graphic output. The vulnerability operates at the intersection of graphics processing and memory safety, exploiting the complex interaction between SVG filter processing and memory management within the browser engine.
The operational impact of CVE-2017-5465 extends beyond simple application instability to potential information disclosure and remote code execution risks. When the out-of-bounds read occurs, the application may inadvertently expose sensitive memory contents such as stack data, heap information, or other process memory to the rendered SVG output. This information disclosure capability provides attackers with valuable insights into memory layout, potentially enabling more sophisticated attacks including heap spraying or other exploitation techniques. The vulnerability affects multiple browser versions simultaneously, creating a significant attack surface across both stable and extended support release channels, with affected versions including Firefox ESR 45.9, Firefox ESR 52.1, Firefox 53, and Thunderbird versions prior to 52.1. The widespread nature of the affected products means that organizations using these versions face substantial risk from both targeted attacks and automated exploit campaigns.
Mitigation strategies for CVE-2017-5465 focus primarily on immediate version updates and patch deployment across all affected Mozilla products. Organizations should prioritize upgrading to patched versions including Firefox 53, Firefox ESR 52.1, Firefox ESR 45.9, and Thunderbird 52.1, as these releases contain the necessary bounds checking fixes for the ConvolvePixel function. Additionally, implementing content security policies that restrict SVG processing and limiting user interaction with untrusted SVG content can provide additional defense-in-depth measures. From a cybersecurity perspective, this vulnerability aligns with CWE-129, which addresses improper validation of array indices, and may map to ATT&CK technique T1059 for execution through web-based attacks. Network administrators should monitor for exploitation attempts targeting this vulnerability and consider implementing web application firewalls or content filtering solutions to block malicious SVG content at the perimeter, while security teams should conduct thorough vulnerability assessments to ensure complete remediation across all affected systems.