An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates.

Published 8 y ago 2018-07-26 · modified 4 mo ago 2026-06-17 · JSON

CVSS

6.5

v3.0 · CNA

CISA KEV

not known exploited

EPSS

3.2%

percentile 88%

Public exploits

none known

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.

Exploit prediction (EPSS)

3.18% probability of exploitation in the next 30 days, higher than 88% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
CNA	3.0	6.5	`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`
NVD	3.1	6.5	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`
CNA	3.0	6.5	`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`
NVD	2.0	4.0	`AV:N/AC:L/Au:S/C:N/I:P/A:N`

Affected products

MIT krb5

Classification

Weakness

CWE-295 Improper Certificate Validation
CWE-287 Improper Authentication

References

github.com /krb5/krb5/pull/694/commits/50fe4074f188c2d4da0c421e96553acea8378db2 · x_refsource_CONFIRM, x_transferred
securityfocus.com /bid/100511 · vdb-entry, x_refsource_BID, x_transferred
github.com /krb5/krb5/pull/694/commits/1de6ca2f2eb1fdbab51f1549a25a6903aefcc196 · x_refsource_CONFIRM, x_transferred
github.com /krb5/krb5/pull/694 · x_refsource_CONFIRM, x_transferred
access.redhat.com /errata/RHSA-2018:0666 · vendor-advisory, x_refsource_REDHAT, x_transferred
github.com /krb5/krb5/pull/694/commits/b7af544e50a4d8291524f590e20dd44430bf627d · x_refsource_CONFIRM, x_transferred
bugzilla.redhat.com /show_bug.cgi?id=CVE-2017-7562 · x_refsource_CONFIRM, x_transferred

Sources

CVE List: CVE-2017-7562
NVD: CVE-2017-7562

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