CVE-2016-2525 in Wireshark
Summary
by MITRE
epan/dissectors/packet-http2.c in the HTTP/2 dissector in Wireshark 2.0.x before 2.0.2 does not limit the amount of header data, which allows remote attackers to cause a denial of service (memory consumption or application crash) via a crafted packet.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-2525 represents a critical denial of service flaw within Wireshark's HTTP/2 protocol dissector implementation. This issue affects Wireshark versions 2.0.x prior to 2.0.2, where the packet-http2.c component fails to impose adequate limits on header data processing. The flaw resides in the dissector's handling of HTTP/2 frames, specifically in how it manages header block data during packet analysis. When processing malformed or crafted HTTP/2 packets, the dissector does not enforce reasonable bounds on header data size, creating an exploitable condition that can be leveraged by remote attackers to disrupt Wireshark's normal operation.
The technical nature of this vulnerability stems from insufficient input validation and resource management within the HTTP/2 dissector module. The dissector processes HTTP/2 header blocks without implementing size constraints, allowing attackers to craft packets containing excessive header data that can cause unbounded memory allocation. This memory consumption issue directly violates the principle of resource exhaustion protection, which is a fundamental security consideration in network protocol analysis tools. The vulnerability enables attackers to consume excessive system resources or trigger application crashes through carefully constructed HTTP/2 packets that exploit the lack of header data limits.
From an operational impact perspective, this vulnerability poses significant risks to network security analysts and forensic investigators who rely on Wireshark for protocol analysis. An attacker could remotely trigger a denial of service condition against any system running vulnerable Wireshark versions, potentially disrupting network monitoring operations, forensic analysis, or security incident response activities. The impact extends beyond simple service disruption as the vulnerability could be exploited to crash the entire Wireshark application, forcing analysts to restart their monitoring sessions and potentially losing valuable network traffic data. This makes the vulnerability particularly dangerous in environments where continuous network monitoring is critical for security operations.
The vulnerability aligns with CWE-770, which addresses allocation of resources without limits or with inadequate limits, and reflects poor resource management practices in protocol dissector implementations. From an ATT&CK framework perspective, this vulnerability could be leveraged during the Defense Evasion and Resource Exhaustion phases of an attack, allowing adversaries to disrupt security monitoring capabilities. The flaw demonstrates a classic lack of input sanitization and boundary checking that is commonly exploited in network protocol analysis tools, where attackers can craft malicious packets to exploit implementation weaknesses. Organizations using Wireshark for security monitoring should prioritize immediate patching to address this vulnerability, as it represents a straightforward path to service disruption that could be exploited in both targeted attacks against monitoring systems and broader network disruption scenarios. The fix implemented in Wireshark 2.0.2 involves adding proper header data size limits to prevent unbounded memory allocation during HTTP/2 packet processing, thereby protecting against this specific denial of service vector.