GLSA 202004-08: libssh: Denial of Service

http://security.gentoo.org/

Severity:	low
Title:	libssh: Denial of Service
Date:	04/10/2020
Bugs:	#716788
ID:	202004-08

Synopsis

A vulnerability in libssh could allow a remote attacker to cause a Denial of Service condition.

Background

libssh is a multiplatform C library implementing the SSHv2 protocol on client and server side.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
net-libs/libssh	< 0.9.4	>= 0.9.4	All supported architectures

Description

It was discovered that libssh could crash when AES-CTR ciphers are used.

Impact

A remote attacker running a malicious client or server could possibly crash the counterpart implemented with libssh and cause a Denial of Service condition.

Workaround

Disable AES-CTR ciphers. If you implement a server using libssh it is recommended to use a prefork model so each session runs in an own process.

Resolution

All libssh users should upgrade to the latest version:

      # emerge --sync
      # emerge --ask --oneshot --verbose ">=net-libs/libssh-0.9.4"

References

CVE-2020-1730

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-202004-08.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.