Inetutils
CVE-2022-39028
HIGH
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
1DescriptionNVD
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.
AnalysisAI
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. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Technical ContextAI
This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. 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. Affected products include: Gnu Inetutils, Mit Kerberos 5, Debian Debian Linux, Netkit-Telnet Project Netkit-Telnet. Version information: through 2.3.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.
GNU Inetutils telnetd through version 2.7 contains a critical authentication bypass that allows remote attackers to gain
GNU inetutils before 2.5 may allow privilege escalation because of unchecked return values of set*id() family functions
Inetutils versions up to 2.7 is affected by inclusion of functionality from untrusted control sphere (CVSS 7.4).
OOB write in GNU inetutils telnetd through 2.7 via LINEMODE SLC handler.
The ftp client in GNU Inetutils before 2.2 does not validate addresses returned by PASV/LSPV responses to make sure they
telnet in GNU inetutils through 2.7 allows servers to read arbitrary environment variables from clients via NEW_ENVIRON
Same weakness CWE-476 – NULL Pointer Dereference
View allSame technique Null Pointer Dereference
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External POC / Exploit Code
Leaving vuln.today