CVE-2021-3738

Description

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.

How to fix CVE-2021-3738

To remediate CVE-2021-3738, upgrade the affected package to a fixed version below.

• —upgrade to 4.13.17-r0 or later
• —upgrade to 2:4.13.13+dfsg-1~deb11u2 or later

Is CVE-2021-3738 being exploited?

Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 4.13.17-r0
• from 0, < 2:4.13.13+dfsg-1~deb11u2

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2021-3738
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2021-3738