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Fencer Intel
high 7.5

CVE-2022-39028 json

telnetd in GNU Inetutils through 2.3, MIT krb5-appl through 1.0.3, and derivative works has a NULL pointer dereference via 0xff 0xf7 or 0xf…

published 4y ago modified 4mo ago also EUVD-2022-41574

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.3%
EPSS 2.3% chance of exploitation in 30 days, percentile 83%
public exploits
0
none known

Summary

telnetd in GNU Inetutils through 2.3, MIT krb5-appl through 1.0.3, and derivative works has a NULL pointer dereference via 0xff 0xf7 or 0xff 0xf8. In a typical installation, the telnetd application would crash but the telnet service would remain available through inetd. However, if the telnetd application has many crashes within a short time interval, the telnet service would become unavailable after inetd logs a "telnet/tcp server failing (looping), service terminated" error. NOTE: MIT krb5-appl is not supported upstream but is shipped by a few Linux distributions. The affected code was removed from the supported MIT Kerberos 5 (aka krb5) product many years ago, at version 1.8.

Patch / fix

  • inetutils Debian 14, Debian 13, Debian 12 2:2.3-5

debian advisories DEBIAN-CVE-2022-39028

  • inetutils Ubuntu 20.04 LTS 2:1.9.4-11ubuntu0.2
  • inetutils Ubuntu 22.04 LTS 2:2.2-2ubuntu0.1
  • inetutils Ubuntu Pro 14.04 LTS 2:1.9.2-1ubuntu0.1~esm2
  • inetutils Ubuntu Pro 16.04 LTS 2:1.9.4-1ubuntu0.1~esm3
  • inetutils Ubuntu Pro 18.04 LTS 2:1.9.4-3ubuntu0.1+esm2

ubuntu advisories UBUNTU-CVE-2022-39028

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

  • telnet SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES for SAP 15 +22 more 1.2-150000.3.6.1
  • telnet SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +5 more 1.2-167.10.1
  • krb5-appl SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +5 more 1.0.3-3.9.1

suse advisories SUSE-SU-2022:3783-1SUSE-SU-2022:3735-1SUSE-SU-2022:3471-1

Is CVE-2022-39028 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.

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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-2022-39028 updated cvss 7.5

krb5-appl: NULL pointer dereference

  • Red Hat Enterprise Linux 6 krb5-appl, krb5-appl-clients, krb5-appl-servers
    affected: no fix planned “Out of support scope”

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

2.35% chance of exploitation in the next 30 days, higher than 83% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • pierrekim.github.io https://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.html referenced PoC, tagged "exploit" by a source, unverified

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:N/A:H

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.