CVE-2021-3738
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.05%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.05% probability · 81th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- samba/samba
- Source
- secalert@redhat.com
EPSS 2.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2021726Issue Tracking, Third Party Advisory
- https://bugzilla.samba.org/show_bug.cgi?id=14468Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/202309-06
- https://www.samba.org/samba/security/CVE-2021-3738.htmlVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2021726Issue Tracking, Third Party Advisory
- https://bugzilla.samba.org/show_bug.cgi?id=14468Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/202309-06
- https://www.samba.org/samba/security/CVE-2021-3738.htmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.