CVE-2020-27777
What it is
A flaw was found in the way RTAS handled memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like local user could use this flaw to further increase their privileges to that of a running kernel.
At a glance
- Exploitability
- Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 6.7 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-862 · Missing authorization
- Record status
- Modified
Affected
- Linux Kernel < 4.14.204
- Linux Kernel < 4.19.155
- Linux Kernel < 5.4.75
- Linux Kernel < 5.9.5
- Redhat Openshift Container Platform 4.4
- Redhat Openshift Container Platform 4.5
- Redhat Openshift Container Platform 4.6
- Redhat Enterprise Linux 5.0
Attack profile CVSS 3.1 · 6.7
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-27777.md and follow it. Check whether this project is affected by CVE-2020-27777. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://bugzilla.redhat.com/show_bug.cgi?id=1900844
- https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764
- https://www.openwall.com/lists/oss-security/2020/10/09/1
- https://bugzilla.redhat.com/show_bug.cgi?id=1900844
- https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764
- https://www.openwall.com/lists/oss-security/2020/10/09/1
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1900844
- https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764
- https://www.openwall.com/lists/oss-security/2020/10/09/1
- https://www.openwall.com/lists/oss-security/2020/11/23/2
- https://bugzilla.redhat.com/show_bug.cgi?id=1900844
- https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764
- https://www.openwall.com/lists/oss-security/2020/10/09/1
- https://www.openwall.com/lists/oss-security/2020/11/23/2