CVE-2012-4179 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsHTMLCSSUtils::CreateCSSPropertyTxn function in Mozilla Firefox before 16.0, Firefox ESR 10.x before 10.0.8, Thunderbird before 16.0, Thunderbird ESR 10.x before 10.0.8, and SeaMonkey before 2.13 allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) via unspecified vectors.
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Analysis
by VulDB Data Team • 10/22/2024
The CVE-2012-4179 vulnerability represents a critical use-after-free flaw within Mozilla Firefox and related products that could enable remote code execution or denial of service conditions. This vulnerability specifically affects the nsHTMLCSSUtils::CreateCSSPropertyTxn function, which handles CSS property transactions during web page rendering processes. The flaw exists in multiple Mozilla products including Firefox versions prior to 16.0, Firefox ESR 10.x versions prior to 10.0.8, Thunderbird versions prior to 16.0, Thunderbird ESR 10.x versions prior to 10.0.8, and SeaMonkey versions prior to 2.13. The vulnerability stems from improper memory management where freed memory locations are accessed after being deallocated, creating opportunities for malicious actors to manipulate heap memory structures.
The technical implementation of this vulnerability involves the manipulation of CSS property transactions within the browser's rendering engine. When the nsHTMLCSSUtils::CreateCSSPropertyTxn function processes certain CSS elements, it fails to properly manage memory references, leading to a scenario where objects are freed from memory but references to them persist. This creates a race condition where attackers can exploit the freed memory locations to inject malicious code or corrupt heap structures. The vulnerability is classified as a use-after-free condition under CWE-416, which specifically addresses the use of memory after it has been freed. The exploitation occurs through unspecified vectors that likely involve crafted CSS content or web pages designed to trigger the specific memory management flaw during CSS processing operations.
From an operational perspective, this vulnerability poses significant risks to users of affected Mozilla products, as it allows remote attackers to execute arbitrary code on vulnerable systems without requiring user interaction. The heap memory corruption resulting from this flaw can lead to system instability, application crashes, or complete system compromise depending on the execution environment. Attackers could potentially leverage this vulnerability to install malware, steal sensitive information, or perform privilege escalation attacks. The impact extends beyond individual user systems to enterprise environments where these browsers are widely deployed, making this vulnerability particularly dangerous in organizational contexts. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, as successful exploitation could provide attackers with elevated system privileges.
Organizations and users should immediately implement mitigations to protect against exploitation of this vulnerability. The primary recommendation involves upgrading to patched versions of affected Mozilla products, specifically Firefox 16.0 and later, Thunderbird 16.0 and later, and SeaMonkey 2.13 and later. Additionally, implementing network-level protections such as content filtering and web application firewalls can help reduce the risk of exploitation. Browser security enhancements including sandboxing, memory protection mechanisms, and strict content security policies should be enabled to limit the potential impact of successful attacks. Regular security updates and patch management procedures should be maintained to ensure all systems remain protected against similar vulnerabilities. The vulnerability demonstrates the importance of proper memory management in browser engines and highlights the critical need for thorough code review processes to identify and remediate use-after-free conditions before they can be exploited in the wild.