CVE-2022-4721 in rdiffweb
Summary
by MITRE • 12/27/2022
Failure to Sanitize Special Elements into a Different Plane (Special Element Injection) in GitHub repository ikus060/rdiffweb prior to 2.5.5.
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Analysis
by VulDB Data Team • 03/09/2026
The vulnerability identified as CVE-2022-4721 represents a critical security flaw in the rdiffweb application that falls under the category of Special Element Injection, a weakness categorized by CWE-74 within the Common Weakness Enumeration framework. This vulnerability exists in the ikus060/rdiffweb repository prior to version 2.5.5 and demonstrates a failure to properly sanitize user input that could be exploited to inject special elements into different processing planes. The application's insufficient validation mechanisms allow malicious actors to manipulate input data that gets processed through different execution contexts, potentially leading to unauthorized access or system compromise.
The technical implementation of this vulnerability stems from the application's inadequate handling of user-supplied data within its web interface and backend processing components. When users interact with the rdiffweb application, particularly when performing operations that involve file paths, directory traversal, or configuration parameters, the system fails to properly sanitize these inputs before they are processed or rendered. This creates an environment where attackers can inject special characters or sequences that alter the intended execution flow of the application. The vulnerability manifests when the application processes user input without adequate filtering or encoding, allowing malicious payloads to be interpreted by different system components that handle the data in distinct processing planes. This cross-plane injection capability significantly amplifies the potential impact of the vulnerability.
The operational impact of CVE-2022-4721 extends beyond simple data corruption or display issues, as it can enable attackers to perform directory traversal attacks, execute arbitrary commands, or gain unauthorized access to system resources. An attacker exploiting this vulnerability could potentially manipulate file system operations, access restricted directories, or even escalate privileges within the application environment. The vulnerability's presence in the rdiffweb repository suggests that organizations relying on this backup and synchronization tool may be exposed to attacks that could compromise their data integrity and system security. This weakness particularly affects environments where the application handles sensitive backup data or operates with elevated privileges, making the potential attack surface more significant.
Organizations utilizing rdiffweb versions prior to 2.5.5 should prioritize immediate remediation through the application's official update channel to address this vulnerability. The fix implemented in version 2.5.5 includes enhanced input validation and sanitization mechanisms that properly encode or filter user-supplied data before processing. Security teams should also implement additional defensive measures such as web application firewalls, input validation rules, and regular security assessments of the application environment. The vulnerability's classification under ATT&CK technique T1059.007 for command and script injection highlights the importance of comprehensive security controls that address multiple attack vectors and prevent exploitation through various system interfaces. Regular monitoring of security advisories and maintaining updated software versions remains essential for preventing exploitation of similar vulnerabilities in the future.