CVE-2016-6508 in Wireshark
Summary
by MITRE
epan/dissectors/packet-rlc.c in the RLC dissector in Wireshark 1.12.x before 1.12.13 and 2.x before 2.0.5 uses an incorrect integer data type, which allows remote attackers to cause a denial of service (large loop) via a crafted packet.
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Analysis
by VulDB Data Team • 09/13/2022
The vulnerability identified as CVE-2016-6508 resides within the Radio Link Control (RLC) dissector component of Wireshark, specifically in the packet-rlc.c file. This flaw affects versions 1.12.x prior to 1.12.13 and 2.x versions prior to 2.0.5, representing a critical issue that could be exploited by remote attackers to disrupt network analysis operations. The vulnerability stems from an improper handling of integer data types during packet processing, which creates a condition where maliciously crafted packets can trigger unexpected behavior in the dissector engine.
The technical root cause of this vulnerability lies in the incorrect use of integer data types within the RLC dissector logic. When Wireshark processes packets containing specific malformed RLC headers, the dissector attempts to iterate through a loop using a variable that has been incorrectly typed. This incorrect typing results in an unexpectedly large loop iteration count, causing the dissector to enter an infinite or extremely prolonged loop. The flaw manifests when the dissector encounters packet structures that contain oversized or malformed length indicators that are interpreted as loop counters, leading to resource exhaustion and system instability.
From an operational perspective, this vulnerability presents a significant risk to network security analysts and forensic investigators who rely on Wireshark for packet analysis. An attacker capable of sending a crafted RLC packet to a system running an affected Wireshark version can cause a denial of service condition that effectively renders the network analysis tool unusable. The impact extends beyond simple disruption as it can prevent security teams from performing critical network monitoring, incident response activities, and forensic analysis. This vulnerability particularly affects environments where Wireshark is used for continuous network monitoring or where automated analysis systems depend on the tool's stability.
The vulnerability aligns with CWE-190, which addresses integer overflow and underflow conditions, and demonstrates how improper integer handling can lead to denial of service scenarios. From an ATT&CK framework perspective, this vulnerability maps to the T1059.007 technique for command and scripting interpreter, as it represents an indirect method of system disruption that can be leveraged to prevent legitimate system operations. The flaw also relates to T1499.004, which covers network disruption through resource exhaustion, as the large loop consumes system resources and potentially leads to complete system unresponsiveness.
Mitigation strategies for CVE-2016-6508 require immediate patching of affected Wireshark installations to versions 1.12.13 or 2.0.5 and later. Network administrators should ensure that all systems running Wireshark are updated promptly, as the vulnerability can be exploited remotely without requiring authentication. Additionally, implementing network segmentation and access controls to limit exposure of Wireshark instances to untrusted networks can provide temporary protection. Organizations should also consider deploying network monitoring solutions that can detect and alert on unusual packet processing patterns that might indicate exploitation attempts. Regular vulnerability assessments and network hygiene practices should include verification of Wireshark versions across all network analysis systems to prevent similar issues from arising in the future.