CVE-2009-2261 in PeaZIP
Summary
by MITRE
PeaZIP 2.6.1, 2.5.1, and earlier on Windows allows user-assisted remote attackers to execute arbitrary commands via a .zip archive with a .txt file whose name contains | (pipe) characters and a command.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/06/2025
The vulnerability identified as CVE-2009-2261 represents a critical command injection flaw in PeaZIP versions 2.6.1, 2.5.1, and earlier on the Windows operating system. This security weakness stems from inadequate input validation within the archive extraction process, specifically when handling filenames containing pipe characters. The vulnerability operates through a user-assisted remote attack vector, meaning that an attacker must convince a victim to open a maliciously crafted archive for the exploit to succeed. The flaw manifests when a .zip archive contains a .txt file with a filename that includes pipe characters followed by arbitrary commands, which PeaZIP processes without proper sanitization.
The technical implementation of this vulnerability resides in the command line argument parsing mechanism within PeaZIP's archive handling functionality. When the software encounters a filename containing pipe characters, it incorrectly interprets the portion following the pipe as a separate command to execute. This behavior violates fundamental security principles of input validation and command execution isolation. The vulnerability maps directly to CWE-78, which describes improper neutralization of special elements used in OS commands, and CWE-88, addressing improper neutralization of argument separators in a command. The flaw essentially allows attackers to inject arbitrary commands into the system shell through the decompression process, creating a path for remote code execution.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the capability to perform arbitrary actions on the victim's system. An attacker could potentially escalate privileges, access sensitive files, modify system configurations, or establish persistence mechanisms through the executed commands. The vulnerability's remote nature means that attackers could distribute malicious archives through various channels including email attachments, web downloads, or compromised websites. The user-assisted aspect reduces the attack surface complexity, as the exploit requires social engineering to convince the victim to open the malicious archive, but once executed, the consequences can be severe.
Mitigation strategies for this vulnerability should focus on immediate software updates to versions that address the command injection flaw. Organizations should implement strict file validation policies that prevent the automatic execution of archives containing suspicious characters or patterns. Network-level defenses can include content filtering systems that scan archive files for potentially malicious naming conventions. Security teams should also consider implementing application whitelisting policies to restrict which applications can perform archive extraction operations. The remediation process should include comprehensive system audits to identify any potential exploitation attempts, along with user education programs to raise awareness about the risks of opening untrusted archive files. This vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in software development, particularly when handling user-supplied data in security-sensitive contexts.