CVE-2012-3964 in Firefox
Summary
by MITRE
Use-after-free vulnerability in the gfxTextRun::GetUserData function in 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 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-2012-3964 vulnerability represents a critical use-after-free condition within Mozilla's graphics text rendering system, specifically affecting the gfxTextRun::GetUserData function. This flaw exists in multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey across their respective versions. The vulnerability stems from improper memory management where freed memory locations are accessed after the original allocation has been released, creating a dangerous state that can be exploited by malicious actors. The issue manifests in the text rendering subsystem that handles complex typography and international character sets, making it particularly concerning given the widespread use of these applications. The vulnerability is classified as a CWE-416 use-after-free condition under the Common Weakness Enumeration framework, which directly relates to improper memory handling practices that have been consistently identified as high-risk security flaws.
The technical exploitation of this vulnerability occurs when malicious web content triggers the text rendering engine to access memory that has already been freed, leading to heap corruption. Attackers can manipulate the text processing pipeline to cause the application to dereference pointers to freed memory locations, potentially allowing for arbitrary code execution or system crashes. The attack vectors are typically initiated through crafted web pages containing malicious text content or embedded fonts that trigger the vulnerable code path during rendering operations. This type of exploitation aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers can leverage the resulting memory corruption to execute malicious payloads within the browser's memory space. The vulnerability's impact extends beyond simple denial of service to full remote code execution capabilities, making it particularly dangerous for enterprise environments where users may encounter malicious content through email or web browsing.
The operational impact of CVE-2012-3964 affects organizations using affected Mozilla products across multiple platforms including Windows, macOS, and Linux systems. The vulnerability's presence in both regular Firefox releases and the Extended Support Release (ESR) versions means that enterprises relying on long-term support channels are also at risk. Organizations may experience unexpected application crashes, system instability, or potentially complete system compromise if attackers successfully exploit the vulnerability. The heap memory corruption can manifest as unpredictable behavior in the browser, including crashes, data corruption, or privilege escalation opportunities. Security teams must consider the widespread adoption of these applications when assessing risk, as the vulnerability affects millions of users globally. The exploitation of such memory corruption vulnerabilities often requires sophisticated attack techniques and may involve multiple stages of exploitation, including information disclosure and privilege escalation to achieve full system compromise.
Mitigation strategies for CVE-2012-3964 primarily involve immediate patching of affected software versions, with Mozilla releasing updates to Firefox 15.0, Thunderbird 15.0, and SeaMonkey 2.12. Organizations should prioritize updating their systems to the latest stable releases and apply security patches as soon as possible. The implementation of web application firewalls and content filtering solutions can provide additional protection layers by blocking malicious content before it reaches the vulnerable applications. Network segmentation and user access controls should be enforced to limit potential attack surfaces, particularly in enterprise environments. Security monitoring should include detection of unusual application behavior or memory access patterns that may indicate exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar memory corruption issues in other applications. The vulnerability also highlights the importance of memory-safe programming practices and regular code reviews focusing on resource management and pointer handling. Organizations should consider implementing exploit prevention measures such as address space layout randomization and data execution prevention to make exploitation more difficult. Additionally, user education regarding safe browsing practices and the avoidance of untrusted web content remains crucial in reducing the attack surface for such vulnerabilities.