Moderate Security Vulnerability in libssh: Denial of Service and Information Disclosure Risks
Summary
RLSA-2026:62217: Moderate: libssh security update. Affects libssh versions < 0:0.10.4-19.el9_8. Fixed in 0:0.10.4-19.el9_8. How to fix ↓
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Background
libssh is an open-source library that implements the SSH protocol, enabling secure communication between client and server applications. It is widely used for secure file transfers and remote command execution. However, recent vulnerabilities have been identified that could compromise the integrity and availability of applications relying on this library.
Vulnerability Detail
The vulnerabilities in libssh include denial of service attacks through various means, such as zero advertised channel packet sizes and oversized SFTP read lengths. Additionally, there are risks of information disclosure via ProxyCommand username expansion and integrity downgrades through OpenSSL AES-GCM tag verification. These vulnerabilities can lead to application crashes, unauthorized access to sensitive information, and potential exploitation by malicious actors.
How To Fix
Minimum fixed version
0:0.10.4-19.el9_8
This is the first release that contains the fix.
sudo dnf update libsshTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider disabling the use of ProxyCommand in your SSH configurations to mitigate the risk of information disclosure until the package can be updated.
Conclusion
The identified vulnerabilities in libssh pose significant risks to applications utilizing this library. It is crucial to update to the latest patched version to mitigate these risks and ensure secure operations. Regular monitoring for vulnerabilities using tools like Vulert can help maintain application security.
See every vulnerability recorded for libssh →
FAQ
libssh is a library that implements the SSH protocol, allowing secure communication for client-server applications.
The vulnerabilities include denial of service attacks, information disclosure, and integrity downgrades.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in your software. Visit Vulert Scanner to check your application without any signup.
The CVSS score of the vulnerabilities in libssh is 6.5, indicating a moderate severity level.
You can update libssh by running the command 'sudo dnf update libssh' in your terminal.
References
Related vulnerabilities
Recent vulnerabilities recorded for libssh.
