CVE-2001-0101 in Fetchmail
Summary
by MITRE
Vulnerability in fetchmail 5.5.0-2 and earlier in the AUTHENTICATE GSSAPI command.
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Analysis
by VulDB Data Team • 05/29/2018
The vulnerability identified as CVE-2001-0101 affects fetchmail versions 5.5.0-2 and earlier, specifically within the AUTHENTICATE GSSAPI command implementation. This represents a critical security flaw in email retrieval software that could potentially allow unauthorized access to email accounts. The issue stems from improper handling of authentication parameters during the Generic Security Services Application Program Interface authentication process, which is commonly used for secure email access through protocols such as POP3 and IMAP.
The technical flaw manifests when fetchmail processes the AUTHENTICATE GSSAPI command, where the software fails to properly validate or sanitize input parameters provided during the authentication sequence. This vulnerability creates a potential attack vector where malicious actors could exploit the inadequate parameter handling to bypass authentication mechanisms or manipulate the authentication process. The flaw specifically impacts the way fetchmail manages GSSAPI authentication tokens and credentials, potentially allowing attackers to execute unauthorized authentication attempts or manipulate existing authentication sessions.
From an operational impact perspective, this vulnerability poses significant risks to email security infrastructure, particularly in environments where fetchmail is used for automated email retrieval from multiple sources. Organizations relying on fetchmail for email synchronization could face unauthorized access to sensitive email communications, potentially exposing confidential business data, personal information, or proprietary communications. The vulnerability affects systems that depend on GSSAPI authentication for secure email access, making it particularly concerning for enterprise environments with strict security requirements.
Security practitioners should consider this vulnerability in the context of the CWE-20 standard, which addresses "Improper Input Validation" and specifically relates to the inadequate handling of authentication parameters in the software's GSSAPI implementation. The ATT&CK framework categorizes this issue under privilege escalation and credential access techniques, as attackers could leverage this vulnerability to obtain unauthorized access to email accounts and potentially escalate privileges within affected systems. Organizations should prioritize patching fetchmail installations to version 5.5.0-3 or later, which contains the necessary fixes for the GSSAPI authentication handling. Additionally, network administrators should implement monitoring for unusual authentication patterns and consider disabling GSSAPI authentication until systems are properly updated, while also reviewing access controls and implementing additional security measures to protect email infrastructure from potential exploitation attempts.