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Fencer Vulns
high 7.5

CVE-2023-5173 json

In a non-standard configuration of Firefox, an integer overflow could have occurred based on network traffic (possibly under influence of a…

published 2023-09-27 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-57510

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

In a non-standard configuration of Firefox, an integer overflow could have occurred based on network traffic (possibly under influence of a local unprivileged webpage), leading to an out-of-bounds write to privileged process memory. *This bug only affects Firefox if a non-standard preference allowing non-HTTPS Alternate Services (`network.http.altsvc.oe`) is enabled.* This vulnerability affects Firefox < 118.

Patch / fix

  • Mozilla Firefox 118
  • firefox Ubuntu 20.04 LTS 118.0.1+build1-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2023-5173

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

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 118.0.1-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:13272-1

Exploit prediction

0.91% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

  • Mozilla Firefox

Classification

Weakness
  • 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.