CVE-2019-12295 in Wireshark
Summary
by MITRE
In Wireshark 3.0.0 to 3.0.1, 2.6.0 to 2.6.8, and 2.4.0 to 2.4.14, the dissection engine could crash. This was addressed in epan/packet.c by restricting the number of layers and consequently limiting recursion.
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Analysis
by VulDB Data Team • 09/24/2023
The vulnerability identified as CVE-2019-12295 represents a critical denial of service flaw within Wireshark's packet dissection engine that affected multiple versions of the popular network protocol analyzer. This issue stems from insufficient bounds checking during the processing of network packets, specifically when handling malformed or specially crafted packet data that triggers excessive recursion within the dissection engine. The vulnerability manifests as a crash condition that can be reliably triggered by analyzing maliciously constructed network traffic, making it particularly dangerous in environments where network analysis tools are deployed for security monitoring or forensic investigations.
The technical root cause of this vulnerability resides in the packet dissection logic within epan/packet.c where the dissection engine lacks proper recursion depth limiting mechanisms. When processing certain packet formats, the dissection engine can recursively call itself multiple times without adequate bounds checking, leading to stack exhaustion and subsequent application crash. This behavior aligns with CWE-674, which describes the weakness of uncontrolled recursion in software systems. The vulnerability is particularly insidious because it can be triggered through legitimate network traffic analysis operations, meaning that any user who analyzes network captures containing malicious packets could inadvertently cause the application to crash, potentially disrupting ongoing network monitoring activities or forensic investigations.
The operational impact of this vulnerability extends beyond simple application instability, as it can be exploited to disrupt network analysis operations in production environments. Attackers could craft specific packet sequences designed to trigger the recursion limit, causing Wireshark to crash and potentially forcing security analysts to restart their analysis sessions. This disruption could be particularly problematic during security incidents where continuous network monitoring is required, as the tool's unavailability could impede incident response activities. The vulnerability also impacts the reliability of network forensic analysis, as analysts may encounter unexpected crashes when examining network captures that contain maliciously crafted packets, potentially leading to incomplete analysis or loss of critical evidence.
The mitigation strategy implemented in the fix involves establishing explicit limits on the number of protocol layers that can be dissected during packet processing, effectively controlling recursion depth and preventing stack overflow conditions. This approach directly addresses the underlying issue by introducing bounds checking that prevents the dissection engine from entering infinite recursion scenarios. The fix aligns with defensive programming practices and represents a common solution pattern for recursion-related vulnerabilities. Organizations should immediately update to the patched versions of Wireshark to prevent exploitation, as the vulnerability does not require any special privileges or authentication to trigger. The implementation of such rate limiting and recursion controls serves as a fundamental security measure that should be considered for other network analysis tools that process untrusted packet data, as similar vulnerabilities could exist in other protocol analysis frameworks. This vulnerability highlights the importance of robust input validation and recursion control mechanisms in network security tools, particularly those that process potentially malicious network traffic from untrusted sources, and demonstrates how seemingly benign network analysis activities can become vectors for system disruption when proper safeguards are not implemented.