CVE-2010-0405 in bzip2
Summary
by MITRE
Integer overflow in the BZ2_decompress function in decompress.c in bzip2 and libbzip2 before 1.0.6 allows context-dependent attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted compressed file.
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Analysis
by VulDB Data Team • 09/25/2021
The vulnerability identified as CVE-2010-0405 represents a critical integer overflow flaw within the bzip2 compression library's decompression functionality. This issue affects versions of bzip2 and libbzip2 prior to 1.0.6, where the BZ2_decompress function in decompress.c contains a mathematical overflow condition that can be exploited by malicious actors. The vulnerability operates at the intersection of software security and computational integrity, specifically targeting the decompression process that handles compressed data streams. The flaw manifests when the decompression algorithm encounters specially crafted compressed files that trigger integer arithmetic overflow conditions during memory allocation calculations.
The technical implementation of this vulnerability stems from inadequate input validation within the decompression routine where integer variables representing buffer sizes or data lengths are not properly checked for overflow conditions before being used in memory allocation operations. When an attacker provides a malformed compressed file containing maliciously constructed header values or length fields, the decompression process performs arithmetic operations that exceed the maximum representable value for the integer data type. This overflow condition results in incorrect memory allocation decisions where the application attempts to allocate either extremely large or negative memory blocks, leading to memory corruption or allocation failures. The vulnerability is classified under CWE-190 as an integer overflow error, specifically involving signed integer overflow in arithmetic operations. The issue demonstrates the classic pattern of insufficient bounds checking in cryptographic and compression libraries where input validation is crucial for preventing exploitation.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling remote code execution in certain circumstances. When the decompression process encounters the overflow condition, applications using vulnerable libbzip2 versions may experience application crashes, segmentation faults, or unpredictable behavior that can be leveraged for more sophisticated attacks. The context-dependent nature of this vulnerability means that exploitation requires specific conditions where the target application processes untrusted compressed data, such as in email attachments, file downloads, or archive extraction scenarios. Attackers can craft compressed files that, when processed by vulnerable applications, trigger the integer overflow and subsequent memory corruption, potentially leading to arbitrary code execution if proper memory management protections are not in place. This vulnerability directly maps to ATT&CK technique T1059.007 for command and script interpreter execution, as the overflow can potentially be used to execute arbitrary code in the context of the vulnerable application.
Mitigation strategies for CVE-2010-0405 primarily focus on immediate version updates to bzip2 1.0.6 or later, which contain the necessary patches to address the integer overflow conditions. System administrators should prioritize patching all systems that utilize vulnerable libbzip2 versions, particularly those that process untrusted compressed data from external sources. Additional protective measures include implementing strict input validation for compressed data, deploying sandboxed environments for decompression operations, and utilizing application whitelisting to prevent execution of vulnerable applications. Network security controls such as intrusion detection systems can be configured to monitor for suspicious compressed file patterns that might indicate exploitation attempts. The vulnerability highlights the importance of robust integer overflow protection in security-critical libraries and demonstrates how seemingly benign compression functionality can become a vector for serious security breaches. Organizations should also implement comprehensive vulnerability management programs that regularly scan for outdated software components and ensure timely patch deployment across all system environments.