CVE-2019-9209 in Wireshark
Summary
by MITRE
In Wireshark 2.4.0 to 2.4.12 and 2.6.0 to 2.6.6, the ASN.1 BER and related dissectors could crash. This was addressed in epan/dissectors/packet-ber.c by preventing a buffer overflow associated with excessive digits in time values.
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Analysis
by VulDB Data Team • 07/26/2023
The vulnerability identified as CVE-2019-9209 represents a critical buffer overflow issue affecting Wireshark network protocol analyzer versions 2.4.0 through 2.4.12 and 2.6.0 through 2.6.6. This flaw resides within the ASN.1 Basic Encoding Rules (BER) dissectors and related protocol parsers that Wireshark employs to decode and display network traffic. The vulnerability manifests when processing malformed ASN.1 time values containing excessive digits, which can cause the dissectors to attempt memory operations beyond allocated buffer boundaries. This type of vulnerability falls under CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to write beyond allocated memory regions. The impact extends beyond simple crashes as it represents a potential denial of service vector that could be exploited in automated scanning or malicious packet crafting scenarios.
The technical implementation of this vulnerability occurs within the epan/dissectors/packet-ber.c file where the ASN.1 BER dissector processes time value fields. When encountering time values with an excessive number of digits, the dissector fails to properly validate input boundaries before performing memory operations. This allows an attacker to craft specially formatted packets containing malformed ASN.1 time fields that trigger the buffer overflow condition. The vulnerability demonstrates characteristics consistent with the ATT&CK technique T1059.007, which involves the execution of malicious code through protocol parsing errors, and T1499.004, which covers network disruption through protocol analysis failures. The specific nature of the flaw suggests that the original code lacked proper input sanitization and boundary checking mechanisms that are essential for robust protocol parsing implementations.
The operational impact of CVE-2019-9209 extends beyond immediate system crashes to create potential security risks in network monitoring environments. When exploited, this vulnerability can cause Wireshark to terminate unexpectedly, disrupting network analysis operations and potentially leading to loss of critical network traffic data. In enterprise environments where Wireshark serves as a primary network troubleshooting tool, such disruptions can severely impact incident response capabilities and network visibility. The vulnerability affects not only individual users but also automated network monitoring systems that rely on Wireshark's protocol analysis capabilities. Organizations utilizing Wireshark for security monitoring, compliance auditing, or network forensic analysis face increased risk of operational disruption when this vulnerability exists in their analysis environments.
Mitigation strategies for CVE-2019-9209 primarily involve immediate software updates to patched versions of Wireshark where the buffer overflow has been addressed through proper input validation and boundary checking. The fix implemented in the packet-ber.c file demonstrates proper defensive programming practices by ensuring that digit count validation occurs before memory allocation and processing. Network administrators should also implement additional monitoring for suspicious packet patterns that might indicate exploitation attempts, particularly in environments where Wireshark is used for continuous network monitoring. Organizations should consider deploying network segmentation and access controls to limit exposure to potentially malicious traffic that could trigger this vulnerability. The remediation process should include comprehensive testing of updated Wireshark installations to ensure that the fix properly addresses the buffer overflow condition while maintaining full protocol analysis functionality. This vulnerability underscores the importance of regular security updates and proper input validation in protocol parsing components, particularly those handling complex data formats like ASN.1 encoded values that are common in telecommunications and security protocols.