HOMEVULNERABILITIESCVE-2022-39028
HIGH

CVE-2022-39028

CWE-476Published: August 30, 2022· Updated: Jun 17, 2026

7.5
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2022-39028 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

Debian1 product(s)
debian linux
gnu1 product(s)
inetutils
mit1 product(s)
kerberos 5
netkit-telnet_project1 product(s)
netkit-telnet
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://git.hadrons.org/cgit/debian/pkgs/inetutils.git/commit/?id=113da8021710d871c7dd72d2a4d5615d42d64289
PATCHhttps://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.html
PATCHhttps://git.hadrons.org/cgit/debian/pkgs/inetutils.git/commit/?id=113da8021710d871c7dd72d2a4d5615d42d64289
PATCHhttps://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/11/msg00033.html
ADVISORYhttps://lists.gnu.org/archive/html/bug-inetutils/2022-08/msg00002.html
ADVISORYhttps://lists.debian.org/debian-lts-announce/2022/11/msg00033.html
ADVISORYhttps://lists.gnu.org/archive/html/bug-inetutils/2022-08/msg00002.html

All References (8)

→
https://git.hadrons.org/cgit/debian/pkgs/inetutils.git/commit/?id=113da8021710d871c7dd72d2a4d5615d42d64289Mailing List · Patch · Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2022/11/msg00033.htmlMailing List · Third Party Advisory
→
https://lists.gnu.org/archive/html/bug-inetutils/2022-08/msg00002.htmlMailing List · Vendor Advisory
→
https://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.htmlExploit · Patch · Third Party Advisory
→
https://git.hadrons.org/cgit/debian/pkgs/inetutils.git/commit/?id=113da8021710d871c7dd72d2a4d5615d42d64289Mailing List · Patch · Vendor Advisory
→
https://lists.debian.org/debian-lts-announce/2022/11/msg00033.htmlMailing List · Third Party Advisory
→
https://lists.gnu.org/archive/html/bug-inetutils/2022-08/msg00002.htmlMailing List · Vendor Advisory
→
https://pierrekim.github.io/blog/2022-08-24-2-byte-dos-freebsd-netbsd-telnetd-netkit-telnetd-inetutils-telnetd-kerberos-telnetd.htmlExploit · Patch · Third Party Advisory

Quick Facts

CVE IDCVE-2022-39028
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-476
CISA KEVNo
Affected4 vendor(s)
PublishedAug 30, 2022

Related CVEs (CWE-476)

CVE-2022-36648
10.0
CVE-2010-2495
10.0
CVE-2015-9073
9.8
CVE-2021-35068
9.8
CVE-2016-10344
9.8
CVE-2015-9043
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2022-39028 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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