CVE-2021-21781

Name: CVE-2021-21781
Creator: NVD / NIST
Published: 2021-08-18T15:15:07.733+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 3.3/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2021-21781 is a low-severity vulnerability rated 3.3/10 on the CVSS scale. An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

An information disclosure vulnerability exists in the ARM SIGPAGE functionality of Linux Kernel v5.4.66 and v5.4.54. The latest version (5.11-rc4) seems to still be vulnerable. A userland application can read the contents of the sigpage, which can leak kernel memory contents. An attacker can read a process’s memory at a specific offset to trigger this vulnerability. This was fixed in kernel releases: 4.14.222 4.19.177 5.4.99 5.10.17 5.11

Metrics

CVSS 3.1

3.3/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.53%

40.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	5.4.54
Linux	Linux Kernel	5.4.66
Oracle	Communications Cloud Native Core Binding Support Function	22.1.3
Oracle	Communications Cloud Native Core Network Exposure Function	22.1.1
Oracle	Communications Cloud Native Core Policy	22.2.0

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1243Exploit, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1243Exploit, Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.htmlPatch, Third Party Advisory

Timeline

Published: Aug 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21781?

How severe is CVE-2021-21781?

CVE-2021-21781 has a CVSS score of 3.3/10 (LOW severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21781?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21781?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST