Local service crash via shared-UID cache aliasing
Published Feb 15, 2021 · Updated Nov 19, 2024
Use-after-free in affected D-Bus branches through 1.13.16 allows local users to crash dbus-daemon on Unix systems. The Unix user database caches one DBusUserInfo under username and UID keys without retaining independent references, so replacing one alias frees an object still held by the other key. Reachability requires distinct usernames with the same UID and matching policy rules; the dangling object can also cause undefined behavior or incorrect authorization decisions.
Summary
What happened
Use-after-free in affected D-Bus branches through 1.13.16 allows local users to crash dbus-daemon on Unix systems. The Unix user database caches one DBusUserInfo under username and UID keys without retaining independent references, so replacing one alias frees an object still held by the other key. Reachability requires distinct usernames with the same UID and matching policy rules; the dangling object can also cause undefined behavior or incorrect authorization decisions.
The record
- CVE
- CVE-2020-35512
- Published
- Feb 15, 2021
- Updated
- Nov 19, 2024
- Vendor
- freedesktop.org
- Product
- D-Bus
- Classifications
- CWE-416, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 15, 2021CVE publishedPublication date reported by the CVE source.
- Nov 19, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 1.10.30 (Fixed: 1.10.32)
- Affected versionversion=<= 1.12.18 (Fixed: >= 1.12.20)
- Affected versionversion=<= 1.13.16 (Fixed: >= 1.13.18)
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo