CVE-2004-1035 in Imap Proxy
Summary
by MITRE
Multiple integer signedness errors in (1) imapcommon.c, (2) main.c, (3) request.c, and (4) select.c for up-imapproxy IMAP proxy 1.2.2 allow remote attackers to cause a denial of service (server crash) and possibly leak sensitive information via certain literal values that are not properly handled when using the IMAP_Line_Read function.
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Analysis
by VulDB Data Team • 05/27/2019
The vulnerability identified as CVE-2004-1035 represents a critical security flaw in the up-imapproxy IMAP proxy version 1.2.2 that stems from multiple integer signedness errors across four core source files including imapcommon.c, main.c, request.c, and select.c. This issue manifests through improper handling of literal values within the IMAP_Line_Read function, creating a pathway for remote attackers to exploit the system. The vulnerability falls under the category of software defects that can lead to system instability and potential information disclosure, making it particularly dangerous in networked environments where IMAP proxy services are deployed.
The technical root cause of this vulnerability lies in the improper management of integer data types during the processing of IMAP protocol communications. When the IMAP_Line_Read function encounters certain literal values, it fails to correctly interpret the signedness of integer variables, leading to unpredictable behavior in the application's memory handling routines. This mismanagement occurs during the parsing and processing of IMAP commands where literal values are used to specify data lengths or offsets. The signedness errors create conditions where integer overflow or underflow scenarios can occur, causing the application to behave erratically and potentially crash. According to CWE classification, this vulnerability maps to CWE-191 Integer Underflow (Wrap or Wraparound) and CWE-190 Integer Overflow or Wraparound, both of which are fundamental software defects that can be exploited for denial of service attacks.
The operational impact of CVE-2004-1035 extends beyond simple service disruption to potentially expose sensitive information through memory leaks that occur during the crash conditions. Remote attackers can exploit this vulnerability by crafting specially formatted IMAP protocol requests that trigger the integer signedness errors, resulting in server crashes that prevent legitimate users from accessing email services. The potential for information leakage adds another dimension to the threat, as attackers may be able to extract memory contents that could contain user credentials, session information, or other sensitive data. This vulnerability affects the availability and integrity of the IMAP proxy service, creating both immediate denial of service conditions and potential long-term information exposure risks.
Mitigation strategies for this vulnerability require immediate patching of the up-imapproxy software to address the integer signedness errors in the affected source files. System administrators should prioritize updating to a patched version of the IMAP proxy software that properly handles integer values during IMAP protocol processing. Network-level protections can include implementing firewall rules that limit access to the IMAP proxy service and monitoring for unusual protocol patterns that might indicate exploitation attempts. Additionally, the implementation of intrusion detection systems that can identify malformed IMAP requests may help detect exploitation attempts before they succeed. Organizations should also consider implementing application-level firewalls or proxy services that can filter and validate IMAP protocol communications before they reach the vulnerable up-imapproxy service, providing an additional layer of defense against this type of attack. The vulnerability demonstrates the importance of proper integer handling in network services and aligns with ATT&CK technique T1499.004 Network Denial of Service, highlighting the need for robust input validation and proper error handling in protocol implementations.