krb5: issues in OTP and PKINIT kdcpreauth modules leading to requires_preauth bypass
Published May 25, 2015
5.8
MEDIUMCVSS 2.0
EPSS 2.81%
Description
The kdcpreauth modules in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.2 do not properly track whether a client's request has been validated, which allows remote attackers to bypass an intended preauthentication requirement by providing (1) zero bytes of data or (2) an arbitrary realm name, related to plugins/preauth/otp/main.c and plugins/preauth/pkinit/pkinit_srv.c.
Affected products
No data.
- 1.12
- 1.12.1
- 1.12.2
- 1.12.3
- 1.13
- 1.13.1
No data.
Red Hat Enterprise Linux 7
krb5-0:1.13.2-10.el7
Fixed · RHSA-2015:2154
Red Hat Enterprise Linux 5
krb5
Not affected
Red Hat Enterprise Linux 6
krb5
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | krb5-0:1.13.2-10.el7 | Fixed | RHSA-2015:2154 |
| Red Hat Enterprise Linux 5 | krb5 | Not affected | n/a |
| Red Hat Enterprise Linux 6 | krb5 | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue does not affect the version of krb5 package as shipped with Red Hat Enterprise Linux 5 and 6.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 3, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 2.81% (0.02807) | 86.02th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.81% (0.02815) | 84.65th | v5 (v2026.06.15) |
| May 9, 2026 | 1.20% (0.01204) | 79.07th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.10% (0.00100) | 25.43th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.43% (0.00431) | 75.33th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.43% (0.00431) | 73.80th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.43% (0.00431) | 70.52th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.21% (0.01213) | 66.61th | v2 (v2022.01.01) |
| Feb 17, 2023 | 1.21% (0.01213) | 66.22th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.21% (0.01213) | 64.21th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.21% (0.01213) | 40.54th | v2 (v2022.01.01) |
References (9)
- http://krbdev.mit.edu/rt/Ticket/Display.html?id=8160 x_refsource_CONFIRMVendor Advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html x_refsource_CONFIRM
- http://www.securityfocus.com/bid/74824 vdb-entryx_refsource_BID
- http://www.ubuntu.com/usn/USN-2810-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2015-2694 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1216133 Issue Tracking
- https://github.com/krb5/krb5/commit/e3b5a5e5267818c97750b266df50b6a3d4649604 x_refsource_CONFIRMVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2015-2694
- https://www.cve.org/CVERecord?id=CVE-2015-2694
| Link | Providers | Tags |
|---|---|---|
| http://krbdev.mit.edu/rt/Ticket/Display.html?id=8160 | x_refsource_CONFIRMVendor Advisory | |
| http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html | x_refsource_CONFIRM | |
| http://www.securityfocus.com/bid/74824 | vdb-entryx_refsource_BID | |
| http://www.ubuntu.com/usn/USN-2810-1 | vendor-advisoryx_refsource_UBUNTU | |
| https://access.redhat.com/security/cve/CVE-2015-2694 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1216133 | Issue Tracking | |
| https://github.com/krb5/krb5/commit/e3b5a5e5267818c97750b266df50b6a3d4649604 | x_refsource_CONFIRMVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-2694 | ||
| https://www.cve.org/CVERecord?id=CVE-2015-2694 |
Change history (0)
No recorded changes yet.