4.9

CVE-2021-20317: debian debian_linux Improper Initialization

Modified
AliasesUBUNTU-CVE-2021-20317DEBIAN-CVE-2021-20317
Published 27-09-2021Last modified 03-08-2024

Vulnerability summary

CVE-2021-20317 is a medium (CVSS 4.9) Improper Initialization vulnerability in debian debian_linux. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 32.2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4.4, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.9/10
010
Medium · v2.0 (NVD)
EPSS score
0.38%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 11 · Related 2
DLA-2843-1DLA-2941-1DSA-5096-1RHSA-2021:4646RHSA-2021:4647RHSA-2021:4648

Timeline

  1. 27-09-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special user privileges to cause a denial of service, slowing and eventually stopping the system while running OSP.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

32%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.38% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, administrative account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu39 products
  • linuxAll versions (No fix recorded) | < 4.4.0-222.255 | < 4.15.0-166.174
  • linux-aws< 4.4.0-1102.107 | < 4.4.0-1138.152 | < 4.15.0-1118.125
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.3All versions (No fix recorded)
  • linux-aws-5.8All versions (No fix recorded)
Debian2 products
Linux1 product

3 vendors · 42 products

References

12 links
Show all 12 references