CVE-2023-3776: Use-after-free in Linux kernel's net/sched: cls_fw component
First published: Fri Jul 21 2023(Updated: )
A flaw in the Linux Kernel found. A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation. If tcf_change_indev() fails, fw_set_parms() will immediately return an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can control the reference counter and set it to zero, they can cause the reference to be freed, leading to a use-after-free vulnerability. Reference: <a href="https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=0323bce598eea038714f941ce2b22541c46d488f">https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=0323bce598eea038714f941ce2b22541c46d488f</a>
Credit: cve-coordination@google.com cve-coordination@google.com cve-coordination@google.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | >=2.6<6.5 | |
| Linux Linux kernel | =6.5-rc1 | |
| F5 Traffix SDC | =5.2.0=5.1.0 | 5.2.0 |
| Linux Linux kernel | >=2.6.12<4.14.322 | |
| Linux Linux kernel | >=4.15<4.19.291 | |
| Linux Linux kernel | >=4.20<5.4.251 | |
| Linux Linux kernel | >=5.5<5.10.188 | |
| Linux Linux kernel | >=5.11<5.15.121 | |
| Linux Linux kernel | >=5.16<6.1.40 | |
| Linux Linux kernel | >=6.2<6.4.5 | |
| Debian Debian Linux | =10.0 | |
| Debian Debian Linux | =11.0 | |
| Debian Debian Linux | =12.0 | |
| redhat/Kernel | <6.5 | 6.5 |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.12.5-1 |
Remedy
If not needed, disable the ability for unprivileged users to create namespaces. To do this temporarily, do: sudo sysctl -w kernel.unprivileged_userns_clone=0 To disable across reboots, do: echo kernel.unprivileged_userns_clone=0 | \ sudo tee /etc/sysctl.d/99-disable-unpriv-userns.conf
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Reference Links
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=0323bce598eea038714f941ce2b22541c46d488f
- https://kernel.dance/0323bce598eea038714f941ce2b22541c46d488f
- http://packetstormsecurity.com/files/175072/Kernel-Live-Patch-Security-Notice-LSN-0098-1.html
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- https://www.debian.org/security/2023/dsa-5480
- https://www.debian.org/security/2023/dsa-5492
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html
- https://security.netapp.com/advisory/ntap-20240202-0003/
- https://launchpad.net/bugs/cve/CVE-2023-3776
- https://my.f5.com/manage/s/article/K000138731
- https://access.redhat.com/errata/RHSA-2023:5091
- https://access.redhat.com/errata/RHSA-2023:5093
- https://access.redhat.com/errata/RHSA-2023:5069
- https://access.redhat.com/errata/RHSA-2023:5221
- https://access.redhat.com/errata/RHSA-2023:5255
- https://access.redhat.com/errata/RHSA-2023:5244
- https://access.redhat.com/errata/RHSA-2023:5628
- https://access.redhat.com/errata/RHSA-2023:5775
- https://access.redhat.com/errata/RHSA-2023:5794
- https://access.redhat.com/errata/RHSA-2023:6799
- https://access.redhat.com/errata/RHSA-2023:6813
- https://access.redhat.com/errata/RHSA-2023:7294
- https://access.redhat.com/errata/RHSA-2023:7389
- https://access.redhat.com/errata/RHSA-2023:7382
- https://access.redhat.com/errata/RHSA-2023:7398
- https://access.redhat.com/errata/RHSA-2023:7410
- https://access.redhat.com/errata/RHSA-2023:7411
- https://access.redhat.com/errata/RHSA-2023:7417
- https://access.redhat.com/errata/RHSA-2023:7424
- https://access.redhat.com/errata/RHSA-2023:7431
- https://access.redhat.com/errata/RHSA-2023:7419
- https://access.redhat.com/errata/RHSA-2023:7434
- https://access.redhat.com/errata/RHSA-2023:7423
- https://access.redhat.com/errata/RHSA-2024:0262
- https://access.redhat.com/errata/RHSA-2024:1831
- https://bugzilla.redhat.com/show_bug.cgi?id=2225097
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-3776
- https://nvd.nist.gov/vuln/detail/CVE-2023-3776
- https://security-tracker.debian.org/tracker/CVE-2023-3776
- https://ubuntu.com/security/CVE-2023-3776
- https://git.kernel.org/linus/0323bce598eea038714f941ce2b22541c46d488f
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