MEDIUM
The Kerberos 5 (aka krb5) PAM module in Apple OS X before 10.12 does not use constant-time operations for determining username validity, which makes it easier for remote attackers to enumerate user accounts via a timing side-channel attack
Published Sep 25, 2016
5.3
MEDIUMCVSS 3.0
EPSS 1.76%
Description
The Kerberos 5 (aka krb5) PAM module in Apple OS X before 10.12 does not use constant-time operations for determining username validity, which makes it easier for remote attackers to enumerate user accounts via a timing side-channel attack.
Affected products
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
5.3 MEDIUM NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Impact Low
Integrity Impact None
Availability Impact None
5.0 MEDIUM NVD
AV:N/AC:L/Au:N/C:P/I:N/A:N
Access Vector Network
Access Complexity Low
Authentication None
Confidentiality Impact Partial
Integrity Impact None
Availability Impact None
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
1.76% 0.01759
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.01759
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 (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.76% (0.01759) | 77.15th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.76% (0.01759) | 74.99th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.47% (0.00466) | 62.32th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.34% (0.00340) | 72.29th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.34% (0.00340) | 70.64th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.34% (0.00340) | 66.85th | 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) |
Weaknesses (1)
References (4)
- http://lists.apple.com/archives/security-announce/2016/Sep/msg00006.html vendor-advisoryx_refsource_APPLEMailing ListVendor Advisory
- http://www.securityfocus.com/bid/93055 vdb-entryx_refsource_BID
- http://www.securitytracker.com/id/1036858 vdb-entryx_refsource_SECTRACK
- https://support.apple.com/HT207170 x_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://lists.apple.com/archives/security-announce/2016/Sep/msg00006.html | vendor-advisoryx_refsource_APPLEMailing ListVendor Advisory | |
| http://www.securityfocus.com/bid/93055 | vdb-entryx_refsource_BID | |
| http://www.securitytracker.com/id/1036858 | vdb-entryx_refsource_SECTRACK | |
| https://support.apple.com/HT207170 | x_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner apple
Published Sep 25, 2016
Updated Aug 6, 2024
Reserved May 11, 2016
Link CVE-2016-4745
CISA Vulnrichment
Updated n/a