cbcvebase.
CVE-2001-0797
published 2001-12-12

CVE-2001-0797: Buffer overflow in login in various System V based operating systems allows remote attackers to execute arbitrary commands via a large number of arguments…

PriorityP271critical10CVSS 2.0
AVNACLAuNCCICAC
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
94.74%
99.9th percentile
Buffer overflow in login in various System V based operating systems allows remote attackers to execute arbitrary commands via a large number of arguments through services such as telnet and rlogin.

Affected

62 ranges· showing 25
VendorProductVersion rangeFixed in
hphp-ux
hphp-ux
hphp-ux
hphp-ux
hphp-ux
hphp-ux
hphp-ux
hphp-ux
ibmaix
ibmaix
ibmaix
ibmaix
ibmaix
scoopenserver
scoopenserver
scoopenserver
scoopenserver
scoopenserver
scoopenserver
scoopenserver
scoopenserver
sgiirix
sgiirix
sgiirix
sgiirix

Detection & IOCsextracted from sources · hover to see the quote

command/bin/echo met::463:1::/:/bin/sh>>/etc/passwd;
path/bin/login
otherTTYPROMPT=<6-char string>
otherNOP sled: 90 1b 80 0e (Solaris SPARC)
otherReturn address: 0x00027184 (Solaris 2.6-8 SPARC)
bytes
ff fc 18 ff fc 1f ff fc 21 ff fc 23 ff fb 22 ff fc 24 ff fb 27 ff fb 00 ff fa 27 00 00 54 54 59 50 52 4f 4d 50 54 01
bytes
ff fd 03 ff fb 18 ff fb 1f ff fb 20 ff fb 21 ff fb 22 ff fb 27 ff fd 05 ff fb 23
bytes
94 10 20 00 21 0b d8 9a a0 14 21 6e 23 0b cb dc a2 14 63 68 d4 23 bf fc e2 23 bf f8 e0 23 bf f4 90 23 a0 0c d4 23 bf f0 d0 23 bf ec 92 23 a0 14 82 10 20 3b 91 d0 20 08 82 10 20 01 91 d0 20 08
bytes
eb 1d 5e 33 c0 50
  • Detect telnet login attempts supplying the TTYPROMPT environment variable (IAC SB ENVIRON / NEW-ENVIRON option 0x27) with a 6-character value — this is the authentication-bypass trigger for CVE-2001-0797 on Solaris telnetd.
  • Alert on telnet sessions to port 23 where the login username field is followed by 64 or more space-separated single-character arguments (e.g., 'bin c c c c … \n'), indicating the many-arguments buffer overflow trigger.
  • Detect the TESO 7350963 exploit's characteristic telnet negotiation byte sequence (send_data_1) at session start: ff fd 03 ff fb 18 ff fb 1f ff fb 20 ff fb 21 ff fb 22 ff fb 27 ff fd 05 ff fb 23.
  • Monitor /etc/passwd for the addition of a passwordless account entry matching the pattern 'met::463:1::/:/bin/sh', which is the backdoor account written by the TESO exploit shellcode.
  • Flag telnet sessions where the Metasploit TTYPROMPT module's negotiation sequence is observed: IAC WONT TTYPE (ff fc 18), followed by IAC WONT NAWS (ff fc 1f), IAC WONT RSPEED (ff fc 21), IAC WONT ENVOPT (ff fc 23), IAC WILL XDISPLOC (ff fb 22), IAC WONT NEWENV (ff fc 24), IAC WILL ENVIRON (ff fb 27), IAC WILL BINARY (ff fb 00), IAC SB ENVIRON (ff fa 27 00 00) with 'TTYPROMPT' followed by delimiter 0x01 and 6 alphanumeric bytes.
  • The vulnerability is triggered via telnet and rlogin services by passing a large number of arguments to /bin/login; monitor for abnormally large login argument counts on these services.
  • The Metasploit manyargs exploit targets the 'bin' user account as the login name; alert on successful logins as 'bin' from remote telnet/dialup sessions, especially on Solaris 2.6–8.
  • ·The TTYPROMPT bypass requires exactly a 6-character value; shorter or longer values may not trigger the authentication bypass integer overflow.
  • ·The TTYPROMPT authentication bypass works for any account except root unless remote root login is explicitly permitted on the target.
  • ·The Metasploit manyargs exploit (exploit/solaris/dialup/manyargs) targets Solaris 2.6–8 SPARC via dialup modem, not directly over a network TCP connection; the return address 0x00027184 and NOP/shellcode are SPARC-specific.
  • ·The TESO 7350963 exploit has separate code paths for X86 and SPARC (controlled by #define X86_FULL_PACKAGE), with different hardcoded GOT/shellcode addresses for each architecture.

CVSS provenance

nvdv2.010.0CRITICALAV:N/AC:L/Au:N/C:C/I:C/A:C
vulncheck10.0CRITICAL
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