CVE-2008-4069 in Firefox
Summary
by MITRE
The XBM decoder in Mozilla Firefox before 2.0.0.17 and SeaMonkey before 1.1.12 allows remote attackers to read uninitialized memory, and possibly obtain sensitive information in opportunistic circumstances, via a crafted XBM image file.
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Analysis
by VulDB Data Team • 08/17/2019
The vulnerability described in CVE-2008-4069 represents a critical memory safety issue within the XBM image decoder component of Mozilla Firefox and SeaMonkey web browsers. This flaw exists in versions prior to Firefox 2.0.0.17 and SeaMonkey 1.1.12, where the software fails to properly initialize memory regions during the processing of XBM image files. XBM or X Bitmap format is a simple bitmap image format used primarily for storing monochrome images, and the vulnerability specifically targets the decoder implementation that handles these file types. The issue stems from insufficient bounds checking and memory initialization practices during image parsing operations, creating a scenario where uninitialized memory segments may be accessed and potentially exposed to attackers.
The technical exploitation of this vulnerability occurs when a remote attacker crafts a malicious XBM image file designed to trigger the flawed memory handling behavior within the browser's image processing pipeline. When the vulnerable browser attempts to decode and render this crafted image, the uninitialized memory regions may contain residual data from previous operations or system memory contents. This uncontrolled memory access can potentially expose sensitive information such as cryptographic keys, session tokens, or other confidential data that might have resided in the memory locations prior to the current operation. The vulnerability is classified under CWE-125 as "Uninitialized Memory Read" and represents a classic example of how improper memory management can lead to information disclosure attacks. The opportunistic nature of this vulnerability means that successful exploitation depends on specific memory conditions and timing, making it particularly challenging to predict and prevent.
The operational impact of CVE-2008-4069 extends beyond simple information disclosure, as it can enable attackers to gather intelligence about the target system or user sessions. In environments where browsers handle sensitive data or where memory contents might contain confidential information, this vulnerability could facilitate more sophisticated attacks. The flaw essentially allows for passive information harvesting, where attackers can collect fragments of memory that might contain session identifiers, encryption keys, or other potentially valuable data. This vulnerability is particularly concerning in the context of the ATT&CK framework under the technique T1005 "Data from Local System" and T1041 "Exfiltration Over C2 Channel" as it provides a mechanism for data extraction through memory access patterns. The vulnerability demonstrates how seemingly benign image processing functionality can become a vector for information leakage, highlighting the importance of memory safety in multimedia processing components.
Mitigation strategies for CVE-2008-4069 primarily involve immediate patching of affected browser versions, with users upgrading to Firefox 2.0.0.17 or later and SeaMonkey 1.1.12 or later. Organizations should implement comprehensive patch management processes to ensure all vulnerable systems are updated promptly. Additional protective measures include configuring web browsers to disable automatic image loading from untrusted sources, implementing content filtering solutions, and monitoring for suspicious image file downloads. Network administrators should also consider implementing web application firewalls that can detect and block malicious XBM file patterns. The vulnerability underscores the importance of input validation and memory initialization practices in software development, particularly for multimedia processing libraries. Security teams should conduct regular vulnerability assessments focusing on image processing components and implement security coding guidelines that prevent uninitialized memory access patterns. Organizations should also consider implementing memory protection mechanisms such as stack canaries and address space layout randomization to further reduce the exploitability of similar vulnerabilities.