CVE-2012-5238 in Wireshark
Summary
by MITRE
epan/dissectors/packet-ppp.c in the PPP dissector in Wireshark 1.8.x before 1.8.3 uses incorrect OUI data structures during the decoding of (1) PPP and (2) LCP data, which allows remote attackers to cause a denial of service (assertion failure and application exit) via a malformed packet.
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Analysis
by VulDB Data Team • 04/14/2021
The vulnerability identified as CVE-2012-5238 affects the PPP dissector component within Wireshark version 1.8.x prior to 1.8.3, representing a critical denial of service weakness that can be exploited remotely by attackers. This flaw specifically resides in the epan/dissectors/packet-ppp.c file where the protocol dissector incorrectly handles Organizationally Unique Identifier (OUI) data structures during the processing of both PPP and Link Control Protocol (LCP) data. The issue manifests when Wireshark encounters malformed packets that contain invalid OUI values, causing the application to fail during packet analysis operations.
The technical implementation of this vulnerability stems from improper validation of OUI data structures within the PPP dissector logic. When Wireshark processes network traffic containing malformed PPP or LCP packets, the dissector attempts to interpret the OUI fields using incorrect data structure layouts or assumptions about the expected format. This leads to assertion failures within the application code where internal consistency checks detect invalid data patterns and trigger application termination. The flaw operates at the protocol analysis layer of Wireshark, specifically targeting the packet decoding functionality that translates raw network data into human-readable protocol information for network analysis purposes.
From an operational perspective, this vulnerability creates significant risks for network security professionals who rely on Wireshark for network monitoring and forensic analysis. Attackers can remotely trigger the denial of service condition by crafting and transmitting specifically formatted malformed PPP packets to a target system running vulnerable Wireshark versions. When the application crashes due to assertion failures, network analysts lose access to critical monitoring capabilities and must restart the application to resume normal operations. This disruption can be particularly problematic during active network investigations or security incident response activities where continuous monitoring is essential for threat detection and analysis.
The vulnerability maps directly to CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1499.004 for network denial of service attacks. The flaw represents a classic case of improper input validation where the application fails to properly sanitize or validate incoming packet data before processing it through the dissector engine. Network defenders should note that this vulnerability affects the core packet analysis functionality of Wireshark, making it particularly dangerous for security operations centers that depend on continuous packet capture and analysis capabilities. The remote exploitability of this condition means that attackers do not need physical access to the target system, allowing for widespread impact across networks where vulnerable Wireshark instances may be deployed.
The recommended mitigation strategy involves immediate upgrading to Wireshark version 1.8.3 or later, which contains the necessary patches to properly validate OUI data structures during PPP and LCP packet processing. Network administrators should also implement network segmentation and access controls to limit exposure of systems running Wireshark to untrusted network traffic. Additional defensive measures include deploying network intrusion detection systems that can identify and block malformed PPP traffic patterns, as well as implementing proper network monitoring to detect potential exploitation attempts. Organizations should also consider implementing automated patch management processes to ensure all network analysis tools remain current with security updates and vulnerability fixes.