CVE-2001-0377 in Inframail
Summary
by MITRE
Infradig Inframail prior to 3.98a allows a remote attacker to create a denial of service via a malformed POST request which includes a space followed by a large string.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 05/26/2019
The vulnerability identified as CVE-2001-0377 affects Infradig Inframail versions prior to 398a, representing a critical denial of service weakness that can be exploited remotely by attackers. This flaw resides in the mail server's handling of HTTP POST requests, specifically when malformed requests containing a space followed by an excessive string length are processed. The vulnerability demonstrates characteristics consistent with improper input validation and resource exhaustion patterns commonly found in web server implementations.
The technical implementation of this vulnerability stems from insufficient validation of incoming POST request data within the Inframail server software. When a remote attacker crafts a malicious request containing a space character followed by a large string payload, the server fails to properly sanitize or limit the input size. This creates a condition where the server attempts to process the malformed data without adequate bounds checking, leading to resource exhaustion or memory corruption. The specific pattern of a space followed by a large string suggests the vulnerability may be related to how the server parses header fields or parameter values, potentially causing buffer overflows or excessive memory allocation during request processing.
The operational impact of this vulnerability extends beyond simple service disruption, as it represents a potential vector for broader attacks against the mail server infrastructure. Remote attackers can exploit this weakness without authentication requirements, making it particularly dangerous in environments where mail servers are exposed to untrusted networks. The denial of service condition can result in complete service unavailability, requiring manual intervention to restore normal operations. This vulnerability directly relates to CWE-129, which addresses improper validation of length of input data, and may also connect to CWE-770, concerning allocation of resources without limits or refreshes. The attack pattern aligns with ATT&CK technique T1499.004, which involves network denial of service attacks through resource exhaustion.
Mitigation strategies for this vulnerability require immediate patching of affected Inframail installations to version 3.98a or later, which contains the necessary input validation fixes. Network administrators should implement rate limiting and request size restrictions at the perimeter firewall or reverse proxy level to prevent exploitation attempts. Additionally, monitoring for unusual POST request patterns containing large string payloads can help detect potential attacks. The fix should include proper input sanitization, length validation, and resource allocation limits to prevent the server from exhausting memory or processing capabilities when encountering malformed requests. System administrators should also consider implementing intrusion detection systems that can identify and alert on suspicious POST request patterns that match the vulnerability characteristics.