In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm
Published Dec 6, 2017
7.5
HIGHCVSS 3.0
EPSS 3.43%
Description
In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm. The parser would unconditionally dereference NULL pointers in that case, leading to a segmentation fault. This is related to the _kdc_as_rep function in kdc/kerberos5.c and the der_length_visible_string function in lib/asn1/der_length.c.
Affected products
No data.
Configuration 1
- 9.0
Configuration 2
- ≤ 7.4.0
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/A:P
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 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (20 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.43% (0.03427) | 88.53th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.43% (0.03427) | 87.34th | v5 (v2026.06.15) |
| Apr 5, 2026 | 3.99% (0.03994) | 88.39th | v4 (v2025.03.14) |
| Mar 30, 2025 | 9.13% (0.09131) | 91.90th | v4 (v2025.03.14) |
| Mar 29, 2025 | 12.11% (0.12113) | 89.66th | v4 (v2025.03.14) |
| Mar 19, 2025 | 9.13% (0.09131) | 91.65th | v4 (v2025.03.14) |
| Mar 18, 2025 | 10.28% (0.10279) | 92.63th | v4 (v2025.03.14) |
| Mar 17, 2025 | 12.26% (0.12263) | 93.30th | v4 (v2025.03.14) |
| Dec 17, 2024 | 34.90% (0.34904) | 97.13th | v3 (v2023.03.01) |
| Jul 2, 2023 | 66.03% (0.66032) | 97.43th | v3 (v2023.03.01) |
| Apr 29, 2023 | 70.66% (0.70660) | 97.50th | v3 (v2023.03.01) |
| Mar 7, 2023 | 75.91% (0.75911) | 97.58th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.32% (0.01319) | 71.27th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.32% (0.01319) | 71.23th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.32% (0.01319) | 69.22th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.32% (0.01319) | 44.98th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.08% (0.02080) | 50.39th | v1 |
| Jan 6, 2022 | 2.08% (0.02080) | 49.89th | v1 |
| Sep 1, 2021 | 2.08% (0.02080) | 77.32th | v1 |
| Apr 14, 2021 | 2.08% (0.02080) | 0.00th | v1 |
References (7)
- http://h5l.org/advisories.html?show=2017-12-08 x_refsource_CONFIRM
- http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html x_refsource_CONFIRM
- http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html x_refsource_MISCThird Party Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 x_refsource_CONFIRMIssue TrackingMailing ListThird Party Advisory
- https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 x_refsource_CONFIRMThird Party Advisory
- https://github.com/heimdal/heimdal/issues/353 x_refsource_CONFIRMPatchThird Party Advisory
- https://www.debian.org/security/2017/dsa-4055 vendor-advisoryx_refsource_DEBIANThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://h5l.org/advisories.html?show=2017-12-08 | x_refsource_CONFIRM | |
| http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html | x_refsource_CONFIRM | |
| http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html | x_refsource_MISCThird Party Advisory | |
| https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 | x_refsource_CONFIRMIssue TrackingMailing ListThird Party Advisory | |
| https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 | x_refsource_CONFIRMThird Party Advisory | |
| https://github.com/heimdal/heimdal/issues/353 | x_refsource_CONFIRMPatchThird Party Advisory | |
| https://www.debian.org/security/2017/dsa-4055 | vendor-advisoryx_refsource_DEBIANThird Party Advisory |
Change history (0)
No recorded changes yet.