CVE-2006-1936 in Ethereal
Summary
by MITRE
Buffer overflow in Ethereal 0.8.5 up to 0.10.14 allows remote attackers to execute arbitrary code via the telnet dissector.
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Analysis
by VulDB Data Team • 06/17/2019
The vulnerability described in CVE-2006-1936 represents a critical buffer overflow flaw within Ethereal network protocol analyzer versions 0.8.5 through 0.10.14. This security issue specifically affects the telnet dissector component of the software, which is responsible for analyzing and displaying telnet protocol traffic within captured network packets. The buffer overflow occurs when Ethereal processes malformed telnet packets that contain overly long data sequences, causing the application to write beyond the allocated memory buffer boundaries. This fundamental memory management error creates an exploitable condition that can be leveraged by remote attackers to gain control over the affected system. The vulnerability exists due to insufficient input validation and bounds checking within the telnet protocol parsing logic, allowing maliciously crafted network traffic to trigger the overflow condition during normal packet processing operations.
The technical exploitation of this vulnerability follows a classic buffer overflow attack pattern where remote attackers can craft specially designed telnet packets containing excessive data lengths that exceed the predetermined buffer size allocated for telnet data processing. When Ethereal attempts to parse these malformed packets through its telnet dissector, the excessive data overflows into adjacent memory regions, potentially overwriting critical program control structures such as return addresses, function pointers, or stack canaries. This memory corruption can be carefully manipulated to redirect program execution flow to attacker-controlled code, enabling arbitrary code execution with the privileges of the Ethereal process. The attack vector is particularly dangerous because it requires no local access or authentication, allowing remote exploitation over network connections where Ethereal might be analyzing traffic from untrusted sources.
The operational impact of CVE-2006-1936 extends beyond simple remote code execution, as it fundamentally compromises the integrity and availability of network monitoring systems that rely on Ethereal for traffic analysis. Organizations using affected versions of Ethereal in production environments face significant risks including complete system compromise, data exfiltration, and potential lateral movement within network infrastructure. The vulnerability affects network security monitoring and forensic analysis capabilities since Ethereal serves as a critical tool for network traffic inspection and protocol analysis. Attackers could exploit this flaw to establish persistent backdoors, escalate privileges, or deploy additional malware while maintaining operational stealth within the network environment. The impact is particularly severe in environments where Ethereal is used for security monitoring, as the compromise of the analysis tool itself creates a false sense of security while simultaneously providing attackers with a powerful foothold for further attacks.
Mitigation strategies for CVE-2006-1936 require immediate action to address the vulnerable software versions and implement additional protective measures. Organizations should prioritize upgrading to Ethereal versions 0.10.15 or later, where the buffer overflow has been patched through proper input validation and memory boundary checks. Network administrators should also implement additional monitoring and filtering mechanisms to prevent malicious telnet traffic from reaching systems running Ethereal. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that violates secure coding practices. From an ATT&CK framework perspective, this vulnerability maps to T1059 for command and scripting interpreter and T1566 for credential access through network protocols, as attackers can leverage the compromised system for further reconnaissance and privilege escalation activities. Organizations should also consider implementing network segmentation, intrusion detection systems, and regular vulnerability assessments to prevent similar issues in other network monitoring tools and protocols.