CVE-2019-8912: Use After Free
In the Linux kernel afalgrelease() in crypto/afalg.c neglects to set a NULL value for a certain structure member, which leads to a use-after-free (UAF) in sockfssetattr.
A local attacker can use this flaw to escalate privileges and take control of the system. Other vendors have considered this a 'network' accessible attack, this claim is unsubstantiated at this time.
Note: The attack vector that allowed the use-after-free mentioned in the original report is not introduced in the Red Hat Enterprise Linux 7, 6 and 5 versions of the kernel.
References:
http://patchwork.ozlabs.org/patch/1042902/
An upstream patch:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9060cb719e61b685ec0102574e10337fa5f445ea
Other sources
In the Linux kernel through 4.20.11, afalgrelease() in crypto/afalg.c neglects to set a NULL value for a certain structure member, which leads to a use-after-free in sockfssetattr.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/kernel-altto a version that resolves this vulnerability.Fixed in 0:4.14.0-115.17.1.el7a - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.180-1Fixed in 6.12.94-1Fixed in 6.12.107-1Fixed in 7.1.12-1Fixed in 7.1.13-1 - Upgrade
Upgrade
Linux kernelto a version that resolves this vulnerability.Fixed in 4.20.11 - Upgrade
Upgrade
Linux kernelto a version that resolves this vulnerability.Patch 1042902
Event History
Frequently Asked Questions
What is the severity of CVE-2019-8912?
CVE-2019-8912 has a high severity rating as it allows local attackers to escalate privileges.
How do I fix CVE-2019-8912?
To mitigate CVE-2019-8912, update to the appropriate kernel version that contains the fix, such as 5.10.223-1 or later.
What systems are affected by CVE-2019-8912?
CVE-2019-8912 affects various Linux kernel versions including those up to 5.0-rc8 and specific distributions like Red Hat and Ubuntu.
Can CVE-2019-8912 be exploited remotely?
No, CVE-2019-8912 can only be exploited by local attackers with access to the system.
Is there a workaround for CVE-2019-8912?
There are no specific workarounds for CVE-2019-8912, so applying the latest updates is recommended.