CVE-2020-28030 in Wireshark
Summary
by MITRE • 11/03/2020
In Wireshark 3.2.0 to 3.2.7, the GQUIC dissector could crash. This was addressed in epan/dissectors/packet-gquic.c by correcting the implementation of offset advancement.
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Analysis
by VulDB Data Team • 12/01/2020
The vulnerability identified as CVE-2020-28030 represents a critical crash issue within Wireshark's GQUIC protocol dissector affecting versions 3.2.0 through 3.2.7. This flaw resides in the network protocol analysis software's ability to dissect and interpret Google QUIC (Quick UDP Internet Connections) traffic, which is a key component for analyzing modern web protocols. The GQUIC dissector is responsible for parsing the binary format of QUIC packets and presenting structured information to network analysts and security professionals. When processing malformed or unexpected GQUIC traffic, the dissector would encounter a condition that caused the application to terminate abruptly, leading to a denial of service scenario that could disrupt network analysis operations.
The technical root cause of this vulnerability stems from improper handling of offset advancement within the packet parsing logic. In protocol dissection, offset advancement refers to the mechanism by which the dissector tracks its position within the packet data structure as it processes different fields and headers. The flaw occurred when the dissector failed to properly advance the parsing cursor through the GQUIC packet structure, resulting in either infinite loops or invalid memory access patterns. This type of error falls under the category of improper handling of offsets and pointer arithmetic, which is commonly classified as CWE-129 in the Common Weakness Enumeration catalog. The vulnerability demonstrates a classic example of buffer over-read conditions where the dissector attempts to access memory locations beyond the valid packet boundaries.
The operational impact of CVE-2020-28030 extends beyond simple application crashes, affecting the reliability and availability of network forensic analysis capabilities. Network security analysts and penetration testers who rely on Wireshark for monitoring and analyzing QUIC traffic would face unexpected disruptions when encountering GQUIC packets, particularly during security assessments or incident response activities. The vulnerability could be exploited by malicious actors to perform denial of service attacks against network monitoring systems that utilize Wireshark for traffic analysis. This scenario would be particularly concerning in environments where continuous network monitoring is critical for security operations, as it could provide an avenue for attackers to disrupt network visibility and analysis capabilities. The issue directly relates to ATT&CK technique T1562.001, which involves disabling or hijacking security tools to avoid detection.
The fix implemented in epan/dissectors/packet-gquic.c addresses the core issue by correcting the offset advancement logic within the GQUIC dissector. This correction ensures that the parsing cursor properly advances through the packet structure according to the expected field sizes and protocol specifications, preventing the invalid memory access conditions that led to crashes. The solution demonstrates proper defensive programming practices by implementing bounds checking and ensuring that all offset calculations are validated against the actual packet length. This type of fix aligns with security best practices for protocol analysis software and represents a fundamental requirement for robust network security tools. The resolution maintains backward compatibility while strengthening the dissector's resilience against malformed packet inputs and preventing potential exploitation scenarios that could compromise the integrity of network analysis operations.