Skip to content
Fencer Intel
medium 6.2

CVE-2021-3756 json

Heap-based Buffer Overflow in hoene/libmysofa

published 5y ago modified 4mo ago also EUVD-2021-27030

cvss
6.2
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

libmysofa is vulnerable to Heap-based Buffer Overflow

Patch / fix

  • hoene hoene/libmysofa 1.2.1
  • libmysofa Debian 14, Debian 13, Debian 12 1.2.1~dfsg0-1

debian advisories DEBIAN-CVE-2021-3756

  • libmysofa Ubuntu 22.04 LTS 1.2.1~dfsg0-1
  • libmysofa Ubuntu Pro 18.04 LTS 0.6~dfsg0-3+deb10u1ubuntu0.1~esm1
  • libmysofa Ubuntu Pro 20.04 LTS 1.0~dfsg0-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-3756

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2021-3756 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-3756 updated cvss 6.2

libmysofa: heap-based buffer overflow in loudness(), mysofa_check() and readOHDRHeaderMessageDataLayout()

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.07% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • huntr.dev https://huntr.dev/bounties/7ca8d9ea-e2a6-4294-af28-70260bb53bc1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 6.2 CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/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
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • hoene hoene/libmysofa

Classification

Weakness

References

Sources

Fencer Intel 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.