CVE-2005-3244 in Ethereal
Summary
by MITRE
The BER dissector in Ethereal 0.10.3 to 0.10.12 allows remote attackers to cause a denial of service (infinite loop) via unknown vectors.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 07/06/2021
The vulnerability identified as CVE-2005-3244 represents a critical denial of service flaw within the BER dissector component of Ethereal network protocol analyzer versions 0.10.3 through 0.10.12. This issue manifests as an infinite loop condition that can be triggered remotely, potentially disrupting network monitoring operations and service availability. The BER dissector is responsible for parsing Basic Encoding Rules structures commonly used in protocols such as LDAP, SNMP, and other ASN.1-based communications, making this vulnerability particularly dangerous in network security environments where such protocols are actively monitored. The unspecified vectors that trigger this condition suggest that attackers can craft specific malformed packets or data structures that cause the dissector to enter an infinite processing loop, consuming system resources and rendering the application unresponsive.
The technical implementation of this vulnerability stems from inadequate input validation within the BER parsing logic of Ethereal's protocol analysis engine. When processing malformed or specially crafted BER-encoded data, the dissector fails to properly handle recursive or nested structures that could lead to infinite loops in the parsing algorithm. This type of vulnerability falls under CWE-838, which encompasses issues related to insufficient input validation and improper handling of recursive data structures. The flaw demonstrates a classic example of how protocol parsers can be exploited through malformed input, particularly in systems that rely heavily on recursive parsing algorithms for complex data structures. The vulnerability is particularly concerning because it operates at the protocol analysis layer, meaning that any network traffic containing maliciously crafted BER data could trigger the denial of service condition without requiring authentication or special privileges from the attacker.
From an operational perspective, this vulnerability presents significant risks to network security monitoring and incident response capabilities. When an Ethereal instance becomes unresponsive due to the infinite loop, network administrators lose visibility into critical network traffic, potentially masking actual security threats or legitimate network issues. The remote exploitation capability means that adversaries can target monitoring systems without physical access or network credentials, making this a particularly attractive vector for service disruption attacks. The impact extends beyond simple availability issues as network security teams may be unable to analyze traffic patterns or identify malicious activities during the period when the application is frozen. This vulnerability directly impacts the integrity of network monitoring operations and can be leveraged as part of broader attack campaigns where network visibility is systematically compromised, aligning with ATT&CK technique T1498 for network denial of service attacks.
Mitigation strategies for CVE-2005-3244 require immediate patching of affected Ethereal versions to 0.10.13 or later, which contain corrected BER parsing logic that properly handles malformed input structures. Organizations should implement network segmentation and monitoring to detect unusual processing patterns that might indicate exploitation attempts. The vulnerability highlights the importance of input validation and robust error handling in protocol analysis tools, emphasizing the need for defensive programming practices that prevent infinite loops through proper boundary checks and timeout mechanisms. System administrators should also consider implementing intrusion detection systems that can monitor for anomalous protocol parsing behavior and automatically alert security teams to potential exploitation attempts. Additionally, regular security assessments of network monitoring tools and protocol analyzers should include testing for similar parsing vulnerabilities to prevent similar issues from arising in other components of the security infrastructure.