CVE-2018-7335 in Wireshark
Summary
by MITRE
In Wireshark 2.4.0 to 2.4.4 and 2.2.0 to 2.2.12, the IEEE 802.11 dissector could crash. This was addressed in epan/crypt/airpdcap.c by rejecting lengths that are too small.
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Analysis
by VulDB Data Team • 02/10/2023
The vulnerability identified as CVE-2018-7335 represents a critical denial of service flaw within Wireshark's IEEE 802.11 protocol dissector implementation. This issue affected multiple versions of the popular network protocol analyzer, specifically targeting releases from 2.4.0 through 2.4.4 and 2.2.0 through 2.2.12. The flaw manifested as a potential crash condition that could be triggered when processing malformed IEEE 802.11 wireless network packets, particularly those containing invalid length parameters within the airpdcap component responsible for handling wireless network captures. The vulnerability falls under the category of improper input validation, where the dissector failed to properly validate packet length parameters before attempting to process them, creating an execution path that could lead to memory corruption and subsequent application termination.
The technical root cause of this vulnerability resides in the epan/crypt/airpdcap.c source file where the airpdcap component processes wireless network captures. The dissector was not properly validating the length fields within IEEE 802.11 frames, allowing attackers to craft specially malformed packets that would cause the application to attempt operations on invalid memory locations. This type of vulnerability aligns with CWE-129, which describes improper validation of length fields, and represents a classic buffer over-read or under-read condition that can occur when applications fail to validate input parameters before processing. The flaw demonstrates how network protocol analyzers can be vulnerable to malformed packet processing, particularly when dealing with wireless protocols that have complex frame structures and multiple length fields that must be validated against expected ranges.
The operational impact of CVE-2018-7335 extends beyond simple application crashes, as it could be exploited by malicious actors to disrupt network monitoring operations in environments where Wireshark is deployed for network analysis and troubleshooting. Network administrators and security analysts who rely on Wireshark for wireless network analysis could find their monitoring tools become unavailable when processing maliciously crafted traffic, potentially creating blind spots in network security monitoring. This vulnerability particularly affects wireless network forensics, penetration testing, and security auditing activities where analysts might encounter unexpected or malicious wireless traffic. The exploitability of this vulnerability is moderate to high since it requires only the ability to capture or inject specific IEEE 802.11 frames with invalid length parameters, which can be achieved through various network attack scenarios including rogue access point deployments or wireless traffic injection attacks.
Mitigation strategies for CVE-2018-7335 involve immediate patching of affected Wireshark installations to versions that include the fix implemented in the airpdcap.c component. The solution specifically addresses the issue by implementing proper length validation that rejects packets with lengths that are too small, preventing the dissector from attempting to process invalid data structures. Organizations should also consider implementing network segmentation and monitoring to detect and prevent the injection of malformed wireless frames into their networks. Additionally, security teams should review their wireless network monitoring procedures to ensure that potential crash conditions are properly handled and that redundant monitoring systems are available to maintain visibility during potential exploitation attempts. This vulnerability highlights the importance of input validation in protocol dissector implementations and aligns with ATT&CK technique T1059.007 for Defense Evasion through application or system exploitation, emphasizing the need for robust validation mechanisms in network security tools.