CVE-2026-105841
Deferred Deferred - Pending Action

OS Command Injection in lrzsz Receive Utility

Publication date: 2026-10-06

Last updated on: 2026-10-06

Assigner: VulnCheck

Description
lrzsz before 0.13.0 contains an OS command injection vulnerability in the lrz receive utility's pipe mode that allows remote senders to execute commands by supplying crafted filenames. When lrz runs under a suffixed name such as lrztar, procheader() in src/lrz.c passes the unescaped ZMODEM/YMODEM filename to popen(), so shell metacharacters execute as the receiving user.

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Meta Information

Published
2026-10-06
Last Modified
2026-10-06
Generated
2026-10-06
AI Q&A
2026-10-06
EPSS Evaluated
N/A
NVD
CVE-2026-105841
EUVD
EUVD-2026-93393

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
Uwe Ohse lrzsz 0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-78 The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

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Executive Summary

lrzsz before version 0.13.0 has an OS command injection flaw in the lrz receive utility's pipe mode. This allows remote senders to execute arbitrary commands by providing specially crafted filenames. When lrz runs under a modified name like lrztar, the procheader() function in src/lrz.c passes the unescaped ZMODEM/YMODEM filename directly to popen(), enabling shell metacharacters to run as the receiving user.

Detection Guidance

To detect this vulnerability, check if lrzsz versions before 0.13.0 are installed on your system. Run 'lrzsz --version' or 'dpkg -l lrzsz' on Debian-based systems. Inspect filenames received via lrz in pipe mode for shell metacharacters or unusual patterns.

Impact Analysis

An attacker could exploit this to run unauthorized commands on your system if you use lrzsz to receive files from untrusted sources. This could lead to data theft, system compromise, or further network infiltration depending on the commands executed.

Compliance Impact

This vulnerability could violate compliance requirements by allowing unauthorized command execution, potentially leading to data breaches. GDPR may require breach notification, while HIPAA could be compromised if protected health information is exposed or altered through exploitation.

Mitigation Strategies

Immediately update lrzsz to version 0.13.0 or later. Disable pipe mode in lrz if not required. Monitor network traffic for suspicious filenames containing shell metacharacters. Restrict user permissions for lrz operations.

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