CVE-2008-1373 in CUPS
Summary
by MITRE
Buffer overflow in the gif_read_lzw function in CUPS 1.3.6 allows remote attackers to have an unknown impact via a GIF file with a large code_size value, a similar issue to CVE-2006-4484.
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Analysis
by VulDB Data Team • 08/08/2019
The vulnerability identified as CVE-2008-1373 represents a critical buffer overflow flaw within the CUPS (Common Unix Printing System) 1.3.6 software suite, specifically within the gif_read_lzw function responsible for processing GIF image files. This vulnerability arises from insufficient input validation when handling the code_size parameter in GIF file structures, creating a condition where maliciously crafted GIF files can trigger memory corruption. The flaw demonstrates characteristics consistent with CWE-121, which describes stack-based buffer overflow conditions, and aligns with ATT&CK technique T1190 for exploitation through malformed input. The vulnerability is particularly concerning as it allows remote attackers to potentially execute arbitrary code or cause denial of service conditions without requiring authentication or privileged access.
The technical implementation of this vulnerability occurs when CUPS processes GIF files containing excessively large code_size values that exceed the allocated buffer space within the gif_read_lzw function. During the decompression process of LZW (Lempel-Ziv-Welch) encoded data, the system fails to properly validate the code_size parameter against the available buffer boundaries. When an attacker crafts a GIF file with an inflated code_size value, the decompression routine attempts to write data beyond the allocated memory buffer, leading to memory corruption that can result in arbitrary code execution, system crashes, or unpredictable behavior. This vulnerability is reminiscent of CVE-2006-4484, which demonstrated similar patterns of buffer overflow exploitation in image processing components, highlighting the persistent nature of such flaws in graphics handling libraries.
The operational impact of CVE-2008-1373 extends beyond simple denial of service conditions to potentially enable remote code execution within the context of the CUPS printing system. Attackers can exploit this vulnerability by uploading or transmitting malicious GIF files to systems running vulnerable CUPS versions, particularly those configured to process or display image files. The attack surface includes web servers, print servers, and any system that accepts or processes GIF images through CUPS functionality. Systems using CUPS for print queue management, web-based printing services, or image processing workflows become prime targets for exploitation. The vulnerability's remote exploitability means that attackers do not require physical access or local privileges, making it particularly dangerous in networked environments where CUPS services are exposed to untrusted users or external networks.
Mitigation strategies for CVE-2008-1373 should prioritize immediate patching of affected CUPS installations to version 1.3.7 or later, which contains the necessary fixes for the buffer overflow condition. Organizations should implement network segmentation to limit access to CUPS services and restrict the types of files that can be processed through the system. Input validation measures should be enhanced to include strict bounds checking for code_size parameters in all image processing components. System administrators should monitor for suspicious file uploads or print job submissions and implement file type filtering to prevent potentially malicious GIF files from entering the processing pipeline. Additionally, deploying intrusion detection systems that can identify patterns associated with exploitation attempts and maintaining up-to-date security monitoring tools will help detect and prevent successful exploitation of this vulnerability. The fix implemented in later CUPS versions addresses the root cause by ensuring proper buffer size validation and implementing robust error handling for malformed LZW data structures.