CVE-2020-25211: Buffer Overflow
First published: Wed Sep 09 2020(Updated: )
A flaw was found in the Linux kernel. A local attacker, able to inject conntrack netlink configuration, could overflow a local buffer causing crashes or triggering the use of incorrect protocol numbers in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Credit: cve@mitre.org cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| redhat/kernel-rt | <0:3.10.0-1160.21.1.rt56.1158.el7 | 0:3.10.0-1160.21.1.rt56.1158.el7 |
| redhat/kernel | <0:3.10.0-1160.21.1.el7 | 0:3.10.0-1160.21.1.el7 |
| redhat/kernel | <0:3.10.0-693.87.1.el7 | 0:3.10.0-693.87.1.el7 |
| redhat/kernel | <0:3.10.0-957.76.1.el7 | 0:3.10.0-957.76.1.el7 |
| redhat/kernel | <0:3.10.0-1062.49.1.el7 | 0:3.10.0-1062.49.1.el7 |
| redhat/kernel-rt | <0:4.18.0-240.10.1.rt7.64.el8_3 | 0:4.18.0-240.10.1.rt7.64.el8_3 |
| redhat/kernel | <0:4.18.0-240.10.1.el8_3 | 0:4.18.0-240.10.1.el8_3 |
| redhat/kernel | <0:4.18.0-147.38.1.el8_1 | 0:4.18.0-147.38.1.el8_1 |
| redhat/kernel-rt | <0:4.18.0-193.46.1.rt13.96.el8_2 | 0:4.18.0-193.46.1.rt13.96.el8_2 |
| redhat/kernel | <0:4.18.0-193.46.1.el8_2 | 0:4.18.0-193.46.1.el8_2 |
| Linux Linux kernel | <=5.8.7 | |
| Debian Debian Linux | =9.0 | |
| Debian Debian Linux | =10.0 | |
| Fedoraproject Fedora | =31 | |
| Fedoraproject Fedora | =32 | |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.11.10-1 6.12.5-1 |
Remedy
To mitigate this issue, prevent module nf_conntrack_netlink from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically. Alternatively, if nf_conntrack_netlink is being used, on Red Hat Enterprise Linux 8, you can disable unprivileged user namespaces by setting user.max_user_namespaces to 0: # echo "user.max_user_namespaces=0" > /etc/sysctl.d/userns.conf # sysctl -p /etc/sysctl.d/userns.conf
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Reference Links
- https://www.cve.org/CVERecord?id=CVE-2020-25211 https://nvd.nist.gov/vuln/detail/CVE-2020-25211 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6
- https://bugzilla.redhat.com/show_bug.cgi?id=1877571
- https://access.redhat.com/errata/RHSA-2021:0857
- https://access.redhat.com/errata/RHSA-2021:0856
- https://access.redhat.com/errata/RHSA-2021:2164
- https://access.redhat.com/errata/RHSA-2021:2355
- https://access.redhat.com/errata/RHSA-2021:1531
- https://access.redhat.com/errata/RHSA-2021:0004
- https://access.redhat.com/errata/RHSA-2021:0003
- https://access.redhat.com/errata/RHSA-2021:0184
- https://access.redhat.com/errata/RHSA-2021:0189
- https://access.redhat.com/errata/RHSA-2021:0774
- https://access.redhat.com/errata/RHSA-2021:0763
- https://access.redhat.com/errata/RHSA-2021:0765
- https://access.redhat.com/security/cve/cve-2020-25211
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6
- https://lists.debian.org/debian-lts-announce/2020/10/msg00028.html
- https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
- https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BL2O4JAMPJG4YMLLJ7JFDHDJRXN4RKTC/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/OLDYVOM4OS55HA45Y3UEVLDHYGFXPZUX/
- https://security.netapp.com/advisory/ntap-20201009-0001/
- https://twitter.com/grsecurity/status/1303646421158109185
- https://www.debian.org/security/2020/dsa-4774
- https://launchpad.net/bugs/cve/CVE-2020-25211
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1877572
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1877571#c3
- https://access.redhat.com/solutions/41278
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BL2O4JAMPJG4YMLLJ7JFDHDJRXN4RKTC/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OLDYVOM4OS55HA45Y3UEVLDHYGFXPZUX/
- https://git.kernel.org/linus/1cc5ef91d2ff94d2bf2de3b3585423e8a1051cb6
- https://security-tracker.debian.org/tracker/CVE-2020-25211
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25211
- https://nvd.nist.gov/vuln/detail/CVE-2020-25211
- https://ubuntu.com/security/CVE-2020-25211
Parent vulnerabilities
(Appears in the following advisories)
- collector/redhat-cve
- collector/nvd-index
- agent/type
- agent/first-publish-date
- collector/launchpad-cve
- source/Launchpad
- collector/redhat-bugzilla
- source/Red Hat
- alias/CVE-2020-25211
- agent/author
- agent/severity
- agent/weakness
- collector/mitre-cve
- source/MITRE
- agent/references
- agent/remedy
- agent/tags
- collector/usn-cve
- source/Ubuntu
- agent/description
- agent/event
- collector/nvd-cve
- source/NVD
- agent/software-canonical-lookup
- agent/last-modified-date
- collector/security-tracker-debian
- source/Debian
- agent/softwarecombine
- agent/trending
- package-manager/redhat
- vendor/linux
- canonical/linux linux kernel
- version/linux linux kernel/5.8.7
- vendor/debian
- canonical/debian debian linux
- version/debian debian linux/9.0
- version/debian debian linux/10.0
- vendor/fedoraproject
- canonical/fedoraproject fedora
- version/fedoraproject fedora/31
- version/fedoraproject fedora/32
- package-manager/debian