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. 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.

Published: 2017-07-13 Last update: 2026-05-13 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-11103 is rated Moderate Risk (64.4/100): CVSS High severity, with high exploitation likelihood (EPSS 5.64%, 90th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2017-11103

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-31 5.28% 5.64% +0.35%
2 2026-05-10 5.71% 5.28% -0.42%
3 2026-04-24 — 5.71% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-11103

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2017-11103

OS Trackers for CVE-2017-11103

vendor priority summary link
alpine — CVE-2017-11103: 1 source package rows (heimdal); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2017-11103
debian not yet assigned CVE-2017-11103 not yet assigned priority: Debian including 2 source packages (heimdal, samba), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. https://security-tracker.debian.org/tracker/CVE-2017-11103
redhat high — https://access.redhat.com/security/cve/CVE-2017-11103
ubuntu medium CVE-2017-11103 medium priority: Ubuntu including 2 source packages (heimdal, samba), 10 status rows across 5 suites (trusty, upstream, xenial, yakkety, zesty): released 8, needs-triage 2. https://ubuntu.com/security/CVE-2017-11103

Affected software / configurations for CVE-2017-11103

Vendor Product Version Raw CPE
heimdal_project heimdal < 7.4.0 cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*
freebsd freebsd — cpe:2.3:o:freebsd:freebsd:-:*:*:*:*:*:*:*
samba samba >= 4.0.0, < 4.4.15 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
samba samba >= 4.5.0, < 4.5.12 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
samba samba >= 4.6.0, < 4.6.6 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
apple iphone_os < 11.0 cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
apple mac_os_x < 10.13.1 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2017-11103

URL Tags
http://www.debian.org/security/2017/dsa-3912 Third Party Advisory
http://www.h5l.org/advisories.html?show=2017-07-11 Broken Link
http://www.securityfocus.com/bid/99551 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1038876 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1039427 Third Party Advisory VDB Entry
https://github.com/heimdal/heimdal/releases/tag/heimdal-7.4.0 Release Notes
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
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