CVE-2001-0913 in Rwhoisd
Summary
by MITRE
Format string vulnerability in Network Solutions Rwhoisd 1.5.7.2 and earlier, when using syslog, allows remote attackers to corrupt memory and possibly execute arbitrary code via a rwhois request that contains format specifiers.
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Analysis
by VulDB Data Team • 10/01/2025
The vulnerability identified as CVE-2001-0913 represents a critical format string flaw in Network Solutions Rwhoisd version 1.5.7.2 and earlier implementations. This vulnerability specifically manifests when the service utilizes syslog functionality for logging operations, creating a dangerous condition where remote attackers can manipulate input parameters to exploit memory corruption behaviors. The flaw stems from improper handling of user-supplied data within format string operations, allowing malicious actors to inject format specifiers that can cause unpredictable memory access patterns.
The technical exploitation of this vulnerability occurs through carefully crafted rwhois requests that contain malicious format specifiers such as %n, %x, or %s. When the vulnerable service processes these requests and passes them directly to syslog functions without proper sanitization, the format string vulnerability enables attackers to read from or write to arbitrary memory locations. This memory corruption can lead to stack smashing, heap corruption, or controlled memory overwrite scenarios that fundamentally compromise the service's operational integrity. The vulnerability falls under the CWE-134 classification for format string vulnerabilities, which specifically addresses weaknesses where format strings are constructed from user-controlled data without proper validation or sanitization.
From an operational perspective, this vulnerability presents significant risks to network infrastructure security as it allows remote code execution without requiring authentication. The rwhois protocol is commonly used for querying whois information about network resources, making this vulnerability particularly dangerous as attackers can exploit it through standard network connections. The memory corruption effects can result in service crashes, denial of service conditions, or more critically, full system compromise where attackers gain arbitrary code execution privileges. The ATT&CK framework categorizes this vulnerability under T1190 for Exploit Public-Facing Application, highlighting its potential for remote exploitation through network services.
Mitigation strategies for CVE-2001-0913 require immediate patching of the affected Network Solutions Rwhoisd versions to address the format string handling issues. Organizations should implement input validation measures that sanitize all user-supplied data before processing, particularly when these inputs are destined for logging functions. The use of secure coding practices such as employing printf-style functions with explicit format string parameters rather than allowing user input to dictate format specifiers provides essential protection. Network segmentation and access controls should be implemented to limit exposure of the rwhois service to trusted networks only, while regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network services. Additionally, monitoring systems should be configured to detect unusual patterns in rwhois service access that might indicate exploitation attempts.