What is CVE-2017-11103?

CVE-2017-11103 is a high-severity vulnerability in Apple Iphone OS, classified under Insufficient Verification of Data Authenticity. CVSS score: 8.1/10. Published 2017-07-13.

How severe is CVE-2017-11103?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2017-11103 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apple Iphone OS

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 modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.051 (92.4th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.051 · newest: 0.051 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-345 — Insufficient Verification of Data Authenticity

Public proof-of-concept exploits

VenalityXT/Red-Team-Tactics

References

support.apple.com/HT208221 (Third Party Advisory)
www.debian.org/security/2017/dsa-3912 (vendor-advisory, Third Party Advisory)
support.apple.com/HT208144 (Third Party Advisory)
www.orpheus-lyre.info/ (Third Party Advisory)
www.freebsd.org/security/advisories/FreeBSD-SA-17:05.heimdal.asc (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/99551 (VDB Entry, Third Party Advisory, vdb-entry)
www.securitytracker.com/id/1039427 (VDB Entry, Third Party Advisory, vdb-entry)
www.samba.org/samba/security/CVE-2017-11103.html (Third Party Advisory)
www.securitytracker.com/id/1038876 (VDB Entry, Third Party Advisory, vdb-entry)
support.apple.com/HT208112 (Third Party Advisory)

Frequently asked questions

What is CVE-2017-11103?: CVE-2017-11103 is a high-severity vulnerability in Apple Iphone OS, classified under Insufficient Verification of Data Authenticity. CVSS score: 8.1/10. Published 2017-07-13.
How severe is CVE-2017-11103?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2017-11103 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.