7.8

CVE-2021-33909: debian debian_linux Integer Overflow or Wraparound

Modified
AliasesRHSA-2021:2722RHSA-2021:2723UBUNTU-CVE-2021-33909
Published 20-07-2021Last modified 04-08-2024

Vulnerability summary

CVE-2021-33909 is a high (CVSS 7.8) Integer Overflow or Wraparound vulnerability in debian debian_linux. EPSS estimates a 9.73% chance of exploitation in the next 30 days, higher than 95.5% of scored vulnerabilities. 2 public exploits are recorded.

Priority
Prioritisepublic exploit

Public exploit (reference, Date unknown)

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (NVD)
EPSS score
9.73%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits2reference

Advisory lineage

Upstream 0 · Downstream 59 · Related 32
DLA-2713-1DLA-2714-1DSA-4941-1LSN-0079-1LSN-0081-1LSN-0083-1

Timeline

  1. 20-07-2021
    PublishedVulnerability first disclosed.
  2. 04-08-2024
    Last modifiedVulnerability information updated.

Description

fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

9.73%

Chance of exploitation in the next 30 days

Percentile

96%

Versus all other CVEs

30-day change

No change 0.00 pp

From 9.73% 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

2 found
  • referenceUnverified

    Exploit Reference (openwall.com)

    Maturity: unknown

  • referenceUnverified

    Exploit Reference (packetstormsecurity.com)

    Maturity: unknown

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.

Redhat61 products
  • bpftool< 0:4.18.0-147.51.2.el8_1
  • bpftool-debuginfo< 0:4.18.0-147.51.2.el8_1
  • kernel< 0:4.18.0-147.51.2.el8_1
  • kernel-abi-whitelists< 0:4.18.0-147.51.2.el8_1
  • kernel-core< 0:4.18.0-147.51.2.el8_1
Ubuntu60 products
  • linux< 3.13.0-186.237 | < 4.4.0-212.244 | < 4.15.0-151.157 | < 5.4.0-80.90
  • linux-aws< 4.4.0-1094.99 | < 4.4.0-1130.144 | < 4.15.0-1109.116 | < 5.4.0-1054.57
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11< 5.11.0-1014.15~20.04.1
  • linux-aws-5.3All versions (No fix recorded)
Debian2 products
Netapp2 products
Fedoraproject1 product
Linux1 product
  • linux_kernel≥ 3.12.43, < 3.13 | ≥ 3.16, < 4.4.276 | ≥ 4.5, < 4.9.276 | ≥ 4.10, < 4.14.240 | ≥ 4.15, < 4.19.198 | ≥ 4.20, < 5.4.134 | ≥ 5.5, < 5.10.52 | ≥ 5.11, < 5.12.19 | ≥ 5.13, < 5.13.4
Oracle1 product
Sonicwall1 product

8 vendors · 129 products

References

39 links
Show all 39 references