Slackware 1023 Published by

An openssh (SSA:2023-200-02) security update has been released for Slackware Linux 15.0.

openssh (SSA:2023-200-02)

openssh (SSA:2023-200-02)

New openssh packages are available for Slackware 15.0 and -current to
fix a security issue.

Here are the details from the Slackware 15.0 ChangeLog:
patches/packages/openssh-9.3p2-i586-1_slack15.0.txz: Upgraded.
This update fixes a security issue:
ssh-agent(1) in OpenSSH between and 5.5 and 9.3p1 (inclusive): remote code
execution relating to PKCS#11 providers.
The PKCS#11 support ssh-agent(1) could be abused to achieve remote code
execution via a forwarded agent socket if the following conditions are met:
* Exploitation requires the presence of specific libraries on the victim
* Remote exploitation requires that the agent was forwarded to an
attacker-controlled system.
Exploitation can also be prevented by starting ssh-agent(1) with an empty
PKCS#11/FIDO allowlist (ssh-agent -P '') or by configuring an allowlist that
contains only specific provider libraries.
This vulnerability was discovered and demonstrated to be exploitable by the
Qualys Security Advisory team.
Potentially-incompatible changes:
* ssh-agent(8): the agent will now refuse requests to load PKCS#11 modules
issued by remote clients by default. A flag has been added to restore the
previous behaviour: "-Oallow-remote-pkcs11".
For more information, see:
(* Security fix *)

Where to find the new packages:

Thanks to the friendly folks at the OSU Open Source Lab
( for donating FTP and rsync hosting
to the Slackware project! :-)

Also see the "Get Slack" section on for
additional mirror sites near you.

Updated package for Slackware 15.0:

Updated package for Slackware x86_64 15.0:

Updated package for Slackware -current:

Updated package for Slackware x86_64 -current:

MD5 signatures:

Slackware 15.0 package:
f2083947439060e937a3e720c8ba2035 openssh-9.3p2-i586-1_slack15.0.txz

Slackware x86_64 15.0 package:
65bc59e75ee1b485ebbb2c5b744fd932 openssh-9.3p2-x86_64-1_slack15.0.txz

Slackware -current package:
95dc2417dcd41443872c894c693be90a n/openssh-9.3p2-i586-1.txz

Slackware x86_64 -current package:
f41ca760cefc726afa5b0c8905d80907 n/openssh-9.3p2-x86_64-1.txz

Installation instructions:

Upgrade the package as root:
# upgradepkg openssh-9.3p2-i586-1_slack15.0.txz

Next, restart the sshd daemon:
# sh /etc/rc.d/rc.sshd restart


Slackware Linux Security Team