SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2017-11103

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.

HIGH 8.1EPSS 5.12%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (5.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
5.12% probability · 92th percentile
CISA KEV
Not listed
Weakness
CWE-345
Affected
heimdal project/heimdal · freebsd/freebsd · samba/samba · apple/iphone os · apple/mac os x · debian/debian linux
Source
cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.