CVE-2016-10209 in libarchive
Summary
by MITRE
The archive_wstring_append_from_mbs function in archive_string.c in libarchive 3.2.2 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted archive file.
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Analysis
by VulDB Data Team • 11/24/2022
The vulnerability identified as CVE-2016-10209 resides within the libarchive library version 3.2.2, specifically within the archive_wstring_append_from_mbs function located in archive_string.c. This flaw represents a critical security issue that enables remote attackers to execute a denial of service attack through carefully crafted archive files. The vulnerability manifests as a NULL pointer dereference condition that ultimately leads to application crashes, effectively disrupting the normal operation of systems relying on libarchive for archive processing. The affected function processes multibyte string conversions to wide character strings, making it a prime target for exploitation in archive handling scenarios where user-supplied data is processed without adequate validation.
From a technical perspective, the vulnerability stems from insufficient input validation within the string conversion process. When the archive_wstring_append_from_mbs function encounters malformed or specially crafted multibyte sequences within archive files, it fails to properly handle the edge cases that result in NULL pointer dereference. This occurs because the function does not adequately check for null return values from internal memory allocation or string conversion operations before proceeding with subsequent operations. The flaw aligns with CWE-476, which categorizes NULL pointer dereference as a common weakness in software development, particularly when dealing with string manipulation and memory handling functions. The vulnerability demonstrates how seemingly benign input processing can become a vector for system disruption when proper error handling mechanisms are absent.
The operational impact of CVE-2016-10209 extends beyond simple service disruption to encompass broader security implications for systems utilizing libarchive. Attackers can leverage this vulnerability to craft malicious archive files that, when processed by applications using the vulnerable library, will trigger crashes and potentially system instability. This makes the vulnerability particularly dangerous in automated processing environments such as email servers, file sharing systems, or content delivery networks where archive files are routinely handled without user intervention. The vulnerability's remote nature means that attackers do not need local access to exploit it, making it a significant concern for networked systems. According to ATT&CK framework category T1499, this vulnerability represents a denial of service attack that can be classified under the "Elevate privileges" and "Resource exhaustion" techniques, as the attack can consume system resources through repeated crashes and potentially lead to service unavailability.
Mitigation strategies for CVE-2016-10209 primarily focus on immediate software updates and implementation of defensive programming practices. The most effective solution involves upgrading to libarchive version 3.2.3 or later, where the vulnerability has been patched through enhanced input validation and proper NULL pointer checks. Organizations should also implement robust input sanitization measures when processing archive files, including validation of file headers and content before any string conversion operations. Additionally, deploying application-level sandboxing techniques and implementing proper error handling can help contain the impact of such vulnerabilities. The fix typically involves adding comprehensive checks for null return values from string conversion functions and ensuring that all memory allocations are properly validated before use. Security monitoring should include detection of unusual application crash patterns and resource consumption spikes that may indicate exploitation attempts. System administrators should also consider implementing network segmentation and access controls to limit exposure of systems that process untrusted archive files, as recommended in the MITRE ATT&CK framework's defensive strategies for preventing privilege escalation and resource exhaustion attacks.