CVE-2011-0445 in Wireshark
Summary
by MITRE
The ASN.1 BER dissector in Wireshark 1.4.0 through 1.4.2 allows remote attackers to cause a denial of service (assertion failure) via crafted packets, as demonstrated by fuzz-2010-12-30-28473.pcap.
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Analysis
by VulDB Data Team • 10/11/2021
The vulnerability identified as CVE-2011-0445 represents a critical denial of service flaw within Wireshark's ASN.1 Basic Encoding Rules dissector component. This issue affects Wireshark versions 1.4.0 through 1.4.2, where the software's packet analysis capabilities become compromised when processing specifically crafted network traffic. The vulnerability manifests as an assertion failure that occurs during the decoding process of ASN.1 encoded data structures, which are commonly used in various network protocols including LDAP, SNMP, and various telecommunications standards. The flaw was demonstrated through a specific packet capture file named fuzz-2010-12-30-28473.pcap, which contained maliciously constructed ASN.1 BER (Basic Encoding Rules) data that triggered the software's assertion mechanism.
The technical root cause of this vulnerability lies in insufficient input validation within Wireshark's ASN.1 BER dissector implementation. When the dissector encounters malformed or unexpected ASN.1 BER encoded data structures, it fails to properly handle the edge cases that arise from malformed encoding sequences. This particular flaw falls under the category of improper input validation and can be classified as CWE-248, which addresses "Uncaught Exception" conditions in software applications. The dissector's failure to properly validate the structure and encoding of ASN.1 data results in an assertion failure, which causes the Wireshark application to terminate unexpectedly rather than gracefully handling the malformed data. This behavior represents a classic denial of service scenario where legitimate network analysis operations are disrupted by maliciously crafted packets.
The operational impact of CVE-2011-0445 extends beyond simple application crashes, as it can severely disrupt network monitoring and forensic analysis operations. Network security professionals and analysts who rely on Wireshark for traffic inspection and protocol analysis may find their investigative capabilities compromised when encountering this vulnerability. The flaw particularly affects environments where automated network monitoring systems depend on continuous Wireshark operation, as any successful exploitation could result in complete disruption of network analysis services. Additionally, the vulnerability demonstrates the importance of proper exception handling in protocol dissector implementations, as the application's inability to gracefully handle malformed data can lead to complete service interruption. This type of vulnerability aligns with ATT&CK technique T1499.001, which covers "Endpoint Denial of Service" through software or hardware failures that cause system resources to become unavailable.
Mitigation strategies for this vulnerability primarily involve immediate upgrading to Wireshark versions that contain the necessary patches, specifically versions 1.4.3 and later where the ASN.1 BER dissector has been corrected to properly handle malformed input. Network administrators should also implement network segmentation and access controls to limit exposure to potentially malicious traffic, while maintaining proper monitoring of network analysis systems for any signs of disruption. The fix implemented by the Wireshark development team typically involves adding proper bounds checking and input validation within the ASN.1 BER parsing routines, ensuring that malformed data sequences do not trigger assertion failures. Organizations should also consider implementing network intrusion detection systems that can identify and block suspicious packet patterns that may attempt to exploit this vulnerability. Regular vulnerability assessments and security updates should be maintained to prevent similar issues from affecting other components of the network analysis infrastructure, as this vulnerability demonstrates the critical need for robust input validation in protocol analysis tools.