[ GLSA 202004-08 ] libssh

[GLSA]

Gentoo Linux Security Advisory

Title: libssh: Denial of Service (GLSA 202004-08)
Severity: low
Exploitable: remote
Date: 2020-04-10
Bug(s): #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: net-libs/libssh
Vulnerable: < 0.9.4
Unaffected: >= 0.9.4
Architectures: 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: