Use After Free Affecting samba-winbind-modules-debuginfo package, versions <2:4.15.5-0.amzn2022


Severity

Recommended
critical

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.16% (54th percentile)

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  • Snyk IDSNYK-AMZN2022-SAMBAWINBINDMODULESDEBUGINFO-2996043
  • published29 Aug 2022
  • disclosed2 Mar 2022

Introduced: 2 Mar 2022

CVE-2021-3738  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2022 samba-winbind-modules-debuginfo to version 2:4.15.5-0.amzn2022 or higher.
This issue was patched in ALAS2022-2022-022.

NVD Description

Note: Versions mentioned in the description apply only to the upstream samba-winbind-modules-debuginfo package and not the samba-winbind-modules-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2022 relevant fixed versions and status.

In DCE/RPC it is possible to share the handles (cookies for resource state) between multiple connections via a mechanism called 'association groups'. These handles can reference connections to our sam.ldb database. However while the database was correctly shared, the user credentials state was only pointed at, and when one connection within that association group ended, the database would be left pointing at an invalid 'struct session_info'. The most likely outcome here is a crash, but it is possible that the use-after-free could instead allow different user state to be pointed at and this might allow more privileged access.

CVSS Scores

version 3.1