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Fencer Intel
critical 9.8

CVE-2017-8911 json

An integer underflow has been identified in the unicode_to_utf8() function in tnef 1.4.14.

published 2017-05-12 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-17851

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

An integer underflow has been identified in the unicode_to_utf8() function in tnef 1.4.14. This might lead to invalid write operations, controlled by an attacker.

Patch / fix

  • tnef Debian 14, Debian 13, Debian 12 1.4.12-1.2

debian advisories DEBIAN-CVE-2017-8911

  • tnef Ubuntu 14.04 LTS 1.4.9-1+deb8u3build0.14.04.1
  • tnef Ubuntu 16.04 LTS 1.4.9-1+deb8u3build0.16.04.1

ubuntu advisories UBUNTU-CVE-2017-8911

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

  • tnef openSUSE Tumbleweed 1.4.18-1.6

opensuse advisories openSUSE-SU-2024:11467-1

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-2017-8911 updated cvss 7.8

tnef: Integer underflow in unicode_to_utf8

  • 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

1.93% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/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

Classification

Weakness
  • CWE-191 Integer Underflow (Wrap or Wraparound)

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.