CVE-2021-3738
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 2.0% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 2.0% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 2.0% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Samba < 4.13.14
- Samba < 4.14.10
- Samba < 4.15.2
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-3738.md and follow it. Check whether this project is affected by CVE-2021-3738. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://bugzilla.samba.org/show_bug.cgi?id=14468
- https://www.samba.org/samba/security/CVE-2021-3738.html
- https://bugzilla.samba.org/show_bug.cgi?id=14468
- https://www.samba.org/samba/security/CVE-2021-3738.html
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2021726
- https://bugzilla.samba.org/show_bug.cgi?id=14468
- https://security.gentoo.org/glsa/202309-06
- https://www.samba.org/samba/security/CVE-2021-3738.html
- https://bugzilla.redhat.com/show_bug.cgi?id=2021726
- https://bugzilla.samba.org/show_bug.cgi?id=14468
- https://security.gentoo.org/glsa/202309-06
- https://www.samba.org/samba/security/CVE-2021-3738.html