CVE-2012-3962 in Firefox
Summary
by MITRE
Mozilla Firefox before 15.0, Firefox ESR 10.x before 10.0.7, Thunderbird before 15.0, Thunderbird ESR 10.x before 10.0.7, and SeaMonkey before 2.12 do not properly iterate through the characters in a text run, which allows remote attackers to execute arbitrary code via a crafted document.
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Analysis
by VulDB Data Team • 10/22/2024
This vulnerability affects multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey versions prior to their respective secure releases. The core issue lies in how these applications handle text rendering operations, specifically in the iteration process through character sequences within text runs. When processing malformed documents containing crafted text elements, the applications fail to properly validate character boundaries during iteration, creating a condition that can be exploited by remote attackers to execute arbitrary code on affected systems. The flaw represents a classic buffer over-read or memory corruption vulnerability that occurs during text processing operations.
The technical implementation of this vulnerability stems from improper boundary checking within the text rendering engine's character iteration logic. When these applications encounter specially crafted documents with malformed text structures, the iterative process that traverses character sequences does not adequately validate the end-of-text conditions or character boundaries. This allows attackers to manipulate the iteration pointer beyond the intended text limits, potentially leading to memory corruption that can be leveraged for code execution. The vulnerability is classified as a memory safety issue that falls under the broader category of buffer overflows or out-of-bounds memory access patterns.
From an operational perspective, this vulnerability presents a significant risk to users of affected Mozilla products as it enables remote code execution without requiring user interaction beyond visiting a malicious webpage or opening a crafted email message. The attack surface is broad given the widespread use of these applications across different operating systems and platforms. Security researchers have noted that exploitation of this vulnerability can lead to complete system compromise, as attackers can leverage the arbitrary code execution capability to install malware, modify system files, or establish persistence mechanisms. The vulnerability is particularly concerning because it operates at the application level and can be triggered through standard web browsing or email operations.
The mitigation strategy for this vulnerability involves immediate deployment of updated software versions from Mozilla that contain fixes for the character iteration logic. Organizations should prioritize patching all affected versions including Firefox 15.0, Thunderbird 15.0, and SeaMonkey 2.12, along with their respective ESR versions. Additionally, implementing network-based protections such as web application firewalls and content filtering solutions can provide additional defense-in-depth layers. Security teams should also consider monitoring for suspicious web traffic patterns and implementing email filtering rules that can detect and block potentially malicious documents. According to the mitre ATT&CK framework, this vulnerability maps to techniques involving code injection and privilege escalation, making it a critical target for immediate remediation efforts. The CWE classification for this issue would be CWE-125: Out-of-bounds Read, which is a well-known weakness that frequently leads to remote code execution vulnerabilities in text processing components.