CVE-2005-4300 in libremail
Summary
by MITRE
Format string vulnerability in the lire_pop function in pop.c in libremail 1.1.0 and earlier, with compiled with the debug option, allows remote attackers to execute arbitrary code via a crafted e-mail or POP server response.
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Analysis
by VulDB Data Team • 07/15/2018
The vulnerability described in CVE-2005-4300 represents a critical format string flaw within the libremail library version 1.1.0 and earlier. This issue specifically affects the lire_pop function in the pop.c file, which is part of a larger email handling system. The vulnerability becomes exploitable when the library is compiled with debug options enabled, creating a dangerous condition where malicious input can be processed through improper format string handling. The flaw exists in the context of email processing where the application receives and parses email messages or responses from POP servers, making it particularly dangerous in networked environments where untrusted data flows through the system.
The technical implementation of this vulnerability stems from improper handling of format strings within the lire_pop function, which processes POP protocol responses and email content. When debug functionality is enabled during compilation, the application uses user-supplied data directly in printf-style functions without proper sanitization or validation. This creates a classic format string vulnerability where an attacker can inject format specifiers into the input data, allowing them to read arbitrary memory locations, modify program execution flow, or execute arbitrary code on the target system. The vulnerability operates at the application level where email parsing routines handle untrusted input from external sources, making it a prime target for remote exploitation.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over affected systems running vulnerable versions of libremail. Remote attackers can leverage this flaw to execute arbitrary commands with the privileges of the affected application, potentially leading to full system compromise. The vulnerability's exploitation does not require authentication or special privileges, making it particularly dangerous in environments where email services are exposed to the internet. Attackers can craft malicious email messages or manipulate POP server responses to trigger the vulnerable code path, potentially leading to data breaches, system infiltration, or denial of service conditions that can affect email services and associated applications.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems, as the most effective solution involves updating to libremail versions that address the format string handling issue. Organizations should disable debug compilation options in production environments where the library is deployed, as these options are specifically mentioned as enabling the vulnerability. Security measures should include input validation and sanitization of email content, implementing proper format string handling practices that prevent user-supplied data from being interpreted as format specifiers. Additionally, network segmentation and firewall rules should be implemented to limit exposure of vulnerable email services to untrusted networks, while monitoring for suspicious email traffic patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-134 which specifically addresses format string vulnerabilities, and represents a technique that could be mapped to ATT&CK tactic TA0002 (execution) and technique T1059.007 (command and scripting interpreter) for exploitation purposes.