openssh-9.3p2

[Bruce Dubbs]

New patch version.

[Xi Ruoyao]

Changes since OpenSSH 9.3

This release fixes a security bug.

Security

Fix CVE-2023-38408 - a condition where specific libaries loaded via ssh-agent(1)'s PKCS#11 support 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 system.
• 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. In addition to removing the main precondition for exploitation, this release removes the ability for remote ssh-agent(1) clients to load PKCS#11 modules by default (see below).

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".

Note that ssh-agent(8) depends on the SSH client to identify requests that are remote. The OpenSSH >=8.9 ssh(1) client does this, but forwarding access to an agent socket using other tools may circumvent this restriction.

[Bruce Dubbs]

Fixed at commits

44ca200bc2 Update to openssh-9.3p2.
ad3de2355d Update to xfsprogs-6.4.0.

[Douglas R. Reno]

SA-11.3-059 issued

[Bruce Dubbs]

Milestone renamed