--- title: "CVE-2019-8912\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2019-8912?format=md keywords: index, follow --- # CVE-2019-8912 Publication date 18 February 2019 Last updated 4 July 2026 --- Ubuntu priority **Medium** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **7.8 · High** [Score breakdown](https://ubuntu.com/security/CVE-2019-8912?format=md#impact-score) Toggle side navigation ## Description In the Linux kernel through 4.20.11, af\_alg\_release() in crypto/af\_alg.c neglects to set a NULL value for a certain structure member, which leads to a use-after-free in sockfs\_setattr. ### From the Ubuntu Security Team It was discovered that a use-after-free vulnerability existed in the user- space API for crypto (af\_alg) implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. [Read the notes from the security team](https://ubuntu.com/security/CVE-2019-8912?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | linux | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-17.18 | | 18.04 LTS bionic | Fixed 4.15.0-47.50 | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not affected | | linux-aws | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-1012.14 | | 18.04 LTS bionic | Fixed 4.15.0-1035.37 | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not affected | | linux-aws-hwe | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Fixed 4.15.0-1035.37~16.04.1 | | 14.04 LTS trusty | Not in release | | linux-azure | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-1014.14 | | 18.04 LTS bionic | Fixed 4.18.0-1014.14~18.04.1 | | 16.04 LTS xenial | Fixed 4.15.0-1041.45 | | 14.04 LTS trusty | Fixed 4.15.0-1041.45~14.04.1 | | linux-azure-edge | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Fixed 4.18.0-1014.14~18.04.1 | | 16.04 LTS xenial | Fixed 4.15.0-1041.45 | | 14.04 LTS trusty | Not in release | | linux-euclid | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-flo | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-gcp | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-1008.9 | | 18.04 LTS bionic | Fixed 4.15.0-1029.31 | | 16.04 LTS xenial | Fixed 4.15.0-1029.31~16.04.1 | | 14.04 LTS trusty | Not in release | | linux-gcp-edge | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Fixed 4.18.0-1008.9~18.04.1 | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-gke | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Ignored end of standard support | | 14.04 LTS trusty | Not in release | | linux-goldfish | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-grouper | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-hwe | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Fixed 4.18.0-17.18~18.04.1 | | 16.04 LTS xenial | Fixed 4.15.0-47.50~16.04.1 | | 14.04 LTS trusty | Not in release | | linux-hwe-edge | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Fixed 4.15.0-47.50~16.04.1 | | 14.04 LTS trusty | Not in release | | linux-kvm | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-1009.9 | | 18.04 LTS bionic | Fixed 4.15.0-1031.31 | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | linux-lts-trusty | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-lts-utopic | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-lts-vivid | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-lts-wily | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-lts-xenial | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not affected | | linux-maguro | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-mako | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-manta | 19.04 disco | Not in release | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not in release | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | | linux-oem | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.15.0-1035.40 | | 18.04 LTS bionic | Fixed 4.15.0-1035.40 | | 16.04 LTS xenial | Ignored end of standard support, was needs-triage | | 14.04 LTS trusty | Not in release | | linux-oracle | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.15.0-1010.12 | | 18.04 LTS bionic | Fixed 4.15.0-1010.12 | | 16.04 LTS xenial | Fixed 4.15.0-1010.12~16.04.1 | | 14.04 LTS trusty | Not in release | | linux-raspi2 | 19.04 disco | Not affected | | 18.10 cosmic | Fixed 4.18.0-1011.13 | | 18.04 LTS bionic | Fixed 4.15.0-1033.35 | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | | linux-snapdragon | 19.04 disco | Not affected | | 18.10 cosmic | Not in release | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Not affected | | 14.04 LTS trusty | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2019-8912?format=md#patch-details) ## Notes --- ### [tyhicks](https://launchpad.net/~tyhicks) NVD has published CVSS metrics that state that the attack vector is "Network" which results in a CRITICAL CVSS score but that does not match Ubuntu's assessment. The attack vector is "Local" since AF\_ALG is a address family that strictly operates locally between a userspace process and the kernel crypto API and the attack requires a specific sequence of operations to be performed on the file descriptor that represents the socket. This has been addressed in a more generic manner, to fix other network families, by this commit in the net tree: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit/?id=ff7b11aa481f682e0e9711abfeb7d03f5cd612bf ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | linux | * Introduced by [86741ec](https://git.kernel.org/linus/86741ec25462e4c8cdce6df2f41ead05568c7d5e), fixed by [9060cb7](https://git.kernel.org/linus/9060cb719e61b685ec0102574e10337fa5f445ea) * Introduced by [86741ec](https://git.kernel.org/linus/86741ec25462e4c8cdce6df2f41ead05568c7d5e), fixed by [ff7b11a](https://git.kernel.org/linus/ff7b11aa481f682e0e9711abfeb7d03f5cd612bf) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 7.8 · High * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Local | | Attack complexity | Low | | Privileges required | Low | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | High | | Integrity impact | High | | Availability impact | High | * Scores | Parameter | Value | | --- | --- | | Base score | 7.8 · High | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-8912) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-8912) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-8912) * [Debian](https://security-tracker.debian.org/tracker/CVE-2019-8912) ### Related Ubuntu Security Notices (USN) + [USN-3930-2](https://usn.ubuntu.com/USN-3930-2) + Linux kernel (HWE) vulnerabilities + 2 April 2019 + [USN-3930-1](https://usn.ubuntu.com/USN-3930-1) + Linux kernel vulnerabilities + 2 April 2019 + [USN-3931-2](https://usn.ubuntu.com/USN-3931-2) + Linux kernel (HWE) vulnerabilities + 2 April 2019 + [USN-3931-1](https://usn.ubuntu.com/USN-3931-1) + Linux kernel vulnerabilities + 2 April 2019 ### Other references *