CVE-2002-0048 in rsync
Summary
by MITRE
Multiple signedness errors (mixed signed and unsigned numbers) in the I/O functions of rsync 2.4.6, 2.3.2, and other versions allow remote attackers to cause a denial of service and execute arbitrary code in the rsync client or server.
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Analysis
by VulDB Data Team • 10/21/2024
The vulnerability identified as CVE-2002-0048 represents a critical security flaw affecting rsync versions 2.4.6, 2.3.2, and potentially other iterations within the software ecosystem. This issue stems from improper handling of signed and unsigned integer types within the input/output processing functions of the rsync protocol implementation, creating a fundamental weakness that can be exploited remotely by malicious actors. The vulnerability classifies under CWE-194, which specifically addresses the issue of signedness errors in programming constructs, where the mixing of signed and unsigned integer operations leads to unpredictable behavior and potential code execution exploits.
The technical implementation of this vulnerability occurs within the core I/O processing mechanisms of rsync, where the software fails to properly validate or convert integer types during data transmission and reception processes. When remote attackers manipulate the data stream sent to rsync clients or servers, they can trigger conditions where signed and unsigned integer comparisons or operations produce unexpected results. This mismanagement of data types creates buffer overflows, memory corruption scenarios, and arbitrary code execution opportunities that can be leveraged by attackers to gain unauthorized access or disrupt service availability. The flaw particularly manifests during file synchronization operations where rsync processes incoming data streams that may contain maliciously crafted integer values designed to exploit the signedness mismatch.
The operational impact of CVE-2002-0048 extends beyond simple denial of service conditions, as the vulnerability provides attackers with the capability to execute arbitrary code on affected systems. This represents a severe compromise of system integrity and confidentiality, as malicious actors can potentially establish persistent access to networked systems that rely on rsync for file synchronization services. The vulnerability affects both client and server implementations, meaning that any system running rsync in either mode could be compromised. Organizations using rsync for critical file transfer operations face significant risk of unauthorized data access, system compromise, or complete service disruption, particularly in environments where rsync is used for automated backup or synchronization processes.
Mitigation strategies for this vulnerability require immediate patching of affected rsync installations to versions that properly address the signedness errors in integer handling. System administrators should prioritize updating to rsync versions that have been verified to contain fixes for the specific integer type mismatches that create this exploit vector. Network segmentation and access controls should be implemented to limit exposure of rsync services to trusted networks only, while monitoring systems should be deployed to detect anomalous data patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and type handling in networked applications, aligning with ATT&CK technique T1210 for exploitation of remote services and T1059 for command execution through compromised systems. Organizations should also conduct comprehensive vulnerability assessments to identify any other applications or systems that may be susceptible to similar signedness errors, as this class of vulnerability can manifest in various software implementations beyond rsync itself.