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CVE-2021-41617

Published: 26 September 2021

sshd in OpenSSH 6.2 through 8.x before 8.8, when certain non-default configurations are used, allows privilege escalation because supplemental groups are not initialized as expected. Helper programs for AuthorizedKeysCommand and AuthorizedPrincipalsCommand may run with privileges associated with group memberships of the sshd process, if the configuration specifies running the command as a different user.

Notes

AuthorNote
seth-arnold
openssh-ssh1 is provided for compatibility with old devices that
cannot be upgraded to modern protocols. Thus we may not provide security
support for this package if doing so would prevent access to equipment.
mdeslaur
Only applies to non-default configurations where
AuthorizedKeysCommand or AuthorizedPrincipalsCommand are used.
sespiros
Cannot reproduce since sshd for all releases drops supplementary
groups early when it starts with setgroups(0, NULL).
Priority

Low

CVSS 3 base score: 7.0

Status

Package Release Status
openssh
Launchpad, Ubuntu, Debian
bionic Needed

focal Needed

hirsute Ignored
(reached end-of-life)
impish Ignored
(reached end-of-life)
jammy Needed

kinetic Needed

trusty Needed

upstream
Released (8.8)
xenial
Released (1:7.2p2-4ubuntu2.10+esm2)
Patches:
upstream: https://github.com/openssh/openssh-portable/commit/f3cbe43e28fe71427d41cfe3a17125b972710455
upstream: https://github.com/openssh/openssh-portable/commit/bf944e3794eff5413f2df1ef37cddf96918c6bde
openssh-ssh1
Launchpad, Ubuntu, Debian
bionic Needed

focal Needed

hirsute Ignored
(reached end-of-life)
impish Ignored
(reached end-of-life)
jammy Needed

kinetic Needed

trusty Does not exist

upstream Ignored
(frozen on openssh 7.5p)
xenial Does not exist