5.5

CVE-2021-33630: NULL-ptr-deref in network sched

Modified
AliasesUBUNTU-CVE-2021-33630DEBIAN-CVE-2021-33630
Published 18-01-2024Last modified 07-05-2025

Vulnerability summary

CVE-2021-33630 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in openatom openeuler. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 27.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.34%
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 3
DLA-3840-1RHSA-2020:1567RHSA-2020:1769

Timeline

  1. 18-01-2024
    PublishedVulnerability first disclosed.
  2. 07-05-2025
    Last modifiedVulnerability information updated.

Description

NULL Pointer Dereference vulnerability in openEuler kernel on Linux (network modules) allows Pointer Manipulation. This vulnerability is associated with program files net/sched/sch_cbs.C. This issue affects openEuler kernel: from 4.19.90 before 4.19.90-2401.3.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.34% 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, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu64 products
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
  • linux-aws-5.13All versions (No fix recorded)
  • linux-aws-5.19All versions (No fix recorded)
Debian1 product
  • linux< 5.3.7-1
Openatom1 product
Openeuler1 product
  • kernel≥ 4.19.90, < 4.19.90-2401.3

4 vendors · 67 products

References

19 links
Show all 19 references