Use After Free in Busybox

CVE-2021-42381

A use-after-free in Busybox's awk applet leads to denial of service and possibly code execution when processing a crafted awk pattern in the hash_init function

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.028 (85.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 85.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-42381: held from 0.026 to 0.028.

EPSS over last 30 days · oldest: 0.026 · newest: 0.028 · change: +0.002

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-42381?
CVE-2021-42381 is a high-severity vulnerability in Busybox, classified under Use After Free. CVSS score: 7.2/10. Published 2021-11-15.
How severe is CVE-2021-42381?
High severity. CVSS v3 base score is 7.2 out of 10.
Is CVE-2021-42381 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.