CVE-2012-1951 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the nsSMILTimeValueSpec::IsEventBased function in Mozilla Firefox 4.x through 13.0, Firefox ESR 10.x before 10.0.6, Thunderbird 5.0 through 13.0, Thunderbird ESR 10.x before 10.0.6, and SeaMonkey before 2.11 allows remote attackers to cause a denial of service (heap memory corruption) or possibly execute arbitrary code by interacting with objects used for SMIL Timing.
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Analysis
by VulDB Data Team • 10/21/2024
The CVE-2012-1951 vulnerability represents a critical use-after-free flaw within the SMIL timing implementation of Mozilla's browser suite, affecting multiple products including Firefox, Thunderbird, and SeaMonkey across several version ranges. This vulnerability resides in the nsSMILTimeValueSpec::IsEventBased function which handles timing specifications for Scalable Vector Graphics and multimedia content. The flaw occurs when the application processes SMIL (Synchronized Multimedia Integration Language) timing elements, particularly when dealing with event-based timing scenarios where objects are manipulated in memory without proper reference counting or validation.
The technical execution of this vulnerability involves a classic use-after-free condition where memory that has been freed is subsequently accessed or referenced by the application. When SMIL timing elements are processed in specific scenarios, particularly those involving event-based timing, the application may free memory associated with timing objects while still maintaining references to them. This creates a situation where attackers can manipulate the freed memory through carefully crafted SMIL content, potentially leading to heap corruption that can be exploited for arbitrary code execution or denial of service.
The operational impact of this vulnerability extends across multiple Mozilla products and their respective version ranges, making it particularly dangerous for widespread exploitation. Attackers can craft malicious web pages or email content containing specially formatted SMIL elements that trigger the vulnerable code path when processed by the affected browsers. The vulnerability's potential for remote code execution means that simply visiting a compromised website or opening a malicious email attachment could result in system compromise. The heap memory corruption aspect provides attackers with multiple exploitation vectors, including potential information disclosure, privilege escalation, or complete system control depending on the execution environment.
Security professionals should note this vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software implementations. The ATT&CK framework categorizes this as a memory corruption vulnerability that could be leveraged for code execution through web-based attacks. Organizations should prioritize immediate patching of affected versions, with Firefox 4.x through 13.0, Thunderbird 5.0 through 13.0, and SeaMonkey before 2.11 requiring urgent updates. Mitigation strategies include implementing content filtering solutions, disabling SMIL processing in browsers where possible, and deploying network-based intrusion detection systems to monitor for exploitation attempts. The vulnerability underscores the importance of proper memory management in multimedia processing components and highlights the need for regular security assessments of complex browser features like SMIL timing implementations.