MIT Kerberos telnet daemon security bypass

kerberos-telnet-security-bypass (33414) The risk level is classified as MediumMedium Risk

Description:

MIT Kerberos could allow a remote attacker to bypass security restrictions, caused by improper checking of usernames by the telnet daemon during authentication. By attempting to login using any known username beginning with "-e", a remote attacker could exploit this vulnerability to bypass security restrictions and gain unauthorized access to the system with the privileges of the supplied username.

Note: If the telnet daemon is configured for authenticated login, this attack is limited to authenticated users.

*CVSS:

Base Score: 10
  Access Vector: Remote
  Access Complexity: Low
  Authentication: Not Required
  Confidentiality Impact: Complete
  Integrity Impact: Complete
  Availability Impact: Complete
 
Temporal Score: 7.4
  Exploitability: Unproven
  Remediation Level: Official-Fix
  Report Confidence: Confirmed

Consequences:

Bypass Security

Remedy:

Refer to MITKRB5-SA-2007-001 for patch or upgrade information. See References.

For Solaris:
Refer to Sun Alert ID: 102867 for patch, upgrade, or suggested workaround information. See References.

For Red Hat Linux (krb5):
Refer to RHSA-2007:0095 for patch, upgrade, or suggested workaround information. See References.

For Gentoo Linux:
Refer to GLSA 200704-02 for patch, upgrade, or suggested workaround information. See References.

For Debian GNU/Linux 3.1 (krb5):
Refer to DSA-1276-1 for patch, upgrade, or suggested workaround information. See References.

For SUSE Linux (krb5):
Refer to SUSE-SA:2007:025 for patch, upgrade, or suggested workaround information. See References.

For Ubuntu Linux (krb5):
Refer to USN-449-1 for patch, upgrade, or suggested workaround information. See References.

For Mandriva Linux:
Refer to MDKSA-2007:077 for patch, upgrade, or suggested workaround information. See References.

For Turbolinux (telnetd):
Refer to TLSA-2007-25 for patch, upgrade, or suggested workaround information. See References.

For Turbolinux (krb5):
Refer to TLSA-2007-24 for patch, upgrade, or suggested workaround information. See References.

For other distributions:
Contact your vendor for upgrade or patch information.

References:

  • MITKRB5-SA-2007-001 : telnetd allows login as arbitrary user.
  • Sun Alert ID: 102867: Security Vulnerability in the SEAM Kerberized telnetd(1M) Daemon May Allow Unauthorized Remote Users to Gain Access to a Solaris Host.
  • ASA-2007-143: krb5 security update (RHSA-2007-0095)
  • ASA-2007-146: Security Vulnerability in the SEAM Kerberized telnetd(1M) Daemon May Allow Unauthorized Remote Users to Gain Access to a Solaris Host (Sun 102867)
  • BID-23281: MIT Kerberos 5 Telnet Daemon Authentication Bypass Vulnerability
  • CVE-2007-0956: The telnet daemon (telnetd) in MIT krb5 before 1.6.1 allows remote attackers to bypass authentication and gain system access via a username beginning with a '-' character, a similar issue to CVE-2007-0882.
  • DSA-1276: krb5 -- several vulnerabilities
  • GLSA-200704-02: MIT Kerberos 5: Arbitrary remote code execution
  • MDKSA-2007:077: Updated krb5 packages fix vulnerabilities
  • MDKSA-2007:077-1: Updated krb5 packages fix vulnerabilities
  • RHSA-2007-0095: Critical: krb5 security update
  • SA24740: Kerberos Multiple Vulnerabilities
  • SA24755: Sun SEAM Kerberized telnetd Daemon Arbitrary User Login
  • SECTRACK ID: 1017848: Kerberos telnetd Grants Access to Remote Users
  • SUSE-SA:2007:025: krb5 security problems

Platforms Affected:

  • Canonical Ubuntu 5.10
  • Canonical Ubuntu 6.06 LTS
  • Canonical Ubuntu 6.10
  • Debian Debian Linux 3.1
  • Debian Debian Linux 4.0
  • Gentoo Linux
  • MandrakeSoft Mandrake Linux 2006 X86_64
  • MandrakeSoft Mandrake Linux 2006
  • MandrakeSoft Mandrake Linux 2007
  • MandrakeSoft Mandrake Linux 2007 X86_64
  • MandrakeSoft Mandrake Linux 2007.1 X86_64
  • MandrakeSoft Mandrake Linux 2007.1
  • MandrakeSoft Mandrake Linux Corporate Server 3.0 X86_64
  • MandrakeSoft Mandrake Linux Corporate Server 3.0
  • MandrakeSoft Mandrake Linux Corporate Server 4.0 X86_64
  • MandrakeSoft Mandrake Linux Corporate Server 4.0
  • MandrakeSoft Mandrake Multi Network Firewall 2.0
  • MIT Kerberos 5-1.3
  • MIT Kerberos 5-1.3.1
  • MIT Kerberos 5-1.3.2
  • MIT Kerberos 5-1.3.3
  • MIT Kerberos 5-1.3.4
  • MIT Kerberos 5-1.3.5
  • MIT Kerberos 5-1.3.6
  • MIT Kerberos 5-1.4
  • MIT Kerberos 5-1.4.1
  • MIT Kerberos 5-1.4.2
  • MIT Kerberos 5-1.4.3
  • MIT Kerberos 5-1.4.4
  • MIT Kerberos 5-1.5
  • MIT Kerberos 5-1.5.1
  • MIT Kerberos 5-1.5.2
  • MIT Kerberos 5-1.5.3
  • MIT Kerberos 5-1.5.4
  • MIT Kerberos 5-1.6
  • Novell OpenSUSE 10.2
  • RedHat Enterprise Linux 2.1 WS
  • RedHat Enterprise Linux 2.1 ES
  • RedHat Enterprise Linux 2.1 AS
  • RedHat Enterprise Linux 3 WS
  • RedHat Enterprise Linux 3 Desktop
  • RedHat Enterprise Linux 3 AS
  • RedHat Enterprise Linux 3 ES
  • RedHat Enterprise Linux 4 Desktop
  • RedHat Enterprise Linux 4 WS
  • RedHat Enterprise Linux 4 ES
  • RedHat Enterprise Linux 4 AS
  • RedHat Enterprise Linux 5 Client Workstation
  • RedHat Enterprise Linux 5 Client
  • RedHat Enterprise Linux 5
  • RedHat Enterprise Linux Desktop 5.0
  • RedHat Linux Advanced Workstation 2.1 Itanium
  • Sun Enterprise Authentication Mechanism 1.0
  • SUSE SuSE Linux 10.0
  • SUSE SuSE Linux 10.1
  • SUSE SuSE Linux 9.3
  • SuSE SuSE SLED 10
  • SuSE SuSE SLES 10
  • Turbolinux Turbolinux 10 Desktop
  • Turbolinux Turbolinux 10 F...
  • Turbolinux Turbolinux 10 Server
  • Turbolinux Turbolinux 10 Server x64 Ed
  • Turbolinux Turbolinux 8 Server
  • Turbolinux Turbolinux Home
  • Turbolinux Turbolinux Multimedia
  • Turbolinux Turbolinux Personal
  • Turbolinux Turbolinux Appliance Server 1.0 Hosting Ed
  • Turbolinux Turbolinux Appliance Server 1.0 Workgroup Ed
  • Turbolinux Turbolinux Appliance Server 2.0

Reported:

Apr 03, 2007

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