CVE-2017-7562

An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.

Published: 2018-07-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2017-7562 is rated Moderate Risk (59.3/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.30%). EPSS rose +2.85% over the last day, indicating growing attacker interest. Review affected assets and schedule 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-2017-7562

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 2026-06-15 0.46% 3.30% +2.85%
2 2026-05-24 0.43% 0.46% +0.03%
3 2026-03-04 — 0.43% —

Full EPSS history (23 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2017-7562

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
6.5 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2017-7562

OS Trackers for CVE-2017-7562

vendor priority summary link
debian unimportant CVE-2017-7562 unimportant priority: Debian including 1 source packages (krb5), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2017-7562
redhat medium — https://access.redhat.com/security/cve/CVE-2017-7562
suse medium CVE-2017-7562 severity moderate: SUSE including 27 source package names (krb5, krb5-1.12.1-38.5.3, …), 197 product×package rows across 37 product lines (HPE Helion OpenStack 8, Magnum Orchestration 7, … (37 product lines)): Known Not Affected 158, Fixed 39. https://www.suse.com/security/cve/CVE-2017-7562/
ubuntu medium CVE-2017-7562 medium priority: Ubuntu including 1 source packages (krb5), 4 status rows across 4 suites (trusty, upstream, xenial, zesty): not-affected 3, needs-triage 1. https://ubuntu.com/security/CVE-2017-7562

Affected software / configurations for CVE-2017-7562

Vendor Product Version Raw CPE
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_desktop 7.0 cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_server 7.0 cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
redhat enterprise_linux_workstation 7.0 cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*
mit kerberos_5 >= 1.0, < 1.16.1 cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*

References for CVE-2017-7562

cvelogic Threat Intelligence