CVE-2017-11103

MEDIUM

Description

Heimdal before 7.4 allows remote attackers to impersonate services with Orpheus' Lyre attacks because it obtains service-principal names in a way that violates the Kerberos 5 protocol specification. In _krb5_extract_ticket() the KDC-REP service name must be obtained from the encrypted version stored in 'enc_part' instead of the unencrypted version stored in 'ticket'. Use of the unencrypted version provides an opportunity for successful server impersonation and other attacks. NOTE: this CVE is only for Heimdal and other products that embed Heimdal code; it does not apply to other instances in which this part of the Kerberos 5 protocol specification is violated.

References

http://www.debian.org/security/2017/dsa-3912

http://www.h5l.org/advisories.html?show=2017-07-11

http://www.securityfocus.com/bid/99551

http://www.securitytracker.com/id/1038876

http://www.securitytracker.com/id/1039427

https://github.com/heimdal/heimdal/releases/tag/heimdal-7.4.0

https://support.apple.com/HT208112

https://support.apple.com/HT208144

https://support.apple.com/HT208221

https://www.freebsd.org/security/advisories/FreeBSD-SA-17:05.heimdal.asc

https://www.orpheus-lyre.info/

https://www.samba.org/samba/security/CVE-2017-11103.html

Details

Source: MITRE

Published: 2017-07-13

Updated: 2017-11-14

Type: CWE-345

Risk Information

CVSS v2.0

Base Score: 6.8

Vector: (AV:N/AC:M/Au:N/C:P/I:P/A:P)

Impact Score: 6.4

Exploitability Score: 8.6

Severity: MEDIUM

CVSS v3.0

Base Score: 8.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 2.2

Severity: HIGH