CVE-2022-39028
In a typical installation, the telnetd application would crash but the telnet service would remain available through inetd.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.10%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 2.10% probability · 81th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- gnu/inetutils · mit/kerberos 5 · debian/debian linux · netkit-telnet project/netkit-telnet
- Source
- cve@mitre.org
References
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.