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Fencer Vulns
critical 9.8

CVE-2021-33797 json

Buffer-overflow in jsdtoa.c in Artifex MuJS in versions 1.0.1 to 1.1.1.

published 2023-04-17 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20474

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits
0
none known

Summary

Buffer-overflow in jsdtoa.c in Artifex MuJS in versions 1.0.1 to 1.1.1. An integer overflow happens when js_strtod() reads in floating point exponent, which leads to a buffer overflow in the pointer *d.

Patch / fix

  • mujs Debian 14, Debian 13, Debian 12 1.1.3-2

debian advisories DEBIAN-CVE-2021-33797

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
21 mo ago

Exploit prediction

0.81% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/ccxvii/mujs/issues/148 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • n/a mujs

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.