CVE-2017-11103

moderate-risk
Published 2017-07-13

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.

Do I need to act?

~
5.7% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.1/10 High
NETWORK / HIGH complexity

Affected Products (8)

Heimdal

Affected Vendors

Debian Freebsd Samba Apple Heimdal Project

References (24)

Third Party Advisory http://www.debian.org/security/2017/dsa-3912
Broken Link http://www.h5l.org/advisories.html?show=2017-07-11
Third Party Advisory http://www.securityfocus.com/bid/99551
Third Party Advisory http://www.securitytracker.com/id/1038876
Third Party Advisory http://www.securitytracker.com/id/1039427
Release Notes https://github.com/heimdal/heimdal/releases/tag/heimdal-7.4.0
Third Party Advisory https://support.apple.com/HT208112
Third Party Advisory https://support.apple.com/HT208144
Third Party Advisory https://support.apple.com/HT208221
Third Party Advisory https://www.freebsd.org/security/advisories/FreeBSD-SA-17:05.heimdal.asc
Third Party Advisory https://www.orpheus-lyre.info/
Third Party Advisory https://www.samba.org/samba/security/CVE-2017-11103.html
Third Party Advisory http://www.debian.org/security/2017/dsa-3912
Broken Link http://www.h5l.org/advisories.html?show=2017-07-11
Third Party Advisory http://www.securityfocus.com/bid/99551
Third Party Advisory http://www.securitytracker.com/id/1038876
Third Party Advisory http://www.securitytracker.com/id/1039427
Release Notes https://github.com/heimdal/heimdal/releases/tag/heimdal-7.4.0
Third Party Advisory https://support.apple.com/HT208112
Third Party Advisory https://support.apple.com/HT208144
and 4 more references
47
/ 100
moderate-risk
Severity 24/34 · High
Exploitability 9/34 · Low
Exposure 14/34 · Moderate