dhcpd: use-after-free error leads crash in IPv6 mode when using mismatched BIND libraries
Published Nov 1, 2019
7.5
HIGHCVSS 3.1
EPSS 8.81%
Description
There had existed in one of the ISC BIND libraries a bug in a function that was used by dhcpd when operating in DHCPv6 mode. There was also a bug in dhcpd relating to the use of this function per its documentation, but the bug in the library function prevented this from causing any harm. All releases of dhcpd from ISC contain copies of this, and other, BIND libraries in combinations that have been tested prior to release and are known to not present issues like this. Some third-party packagers of ISC software have modified the dhcpd source, BIND source, or version matchup in ways that create the crash potential. Based on reports available to ISC, the crash probability is large and no analysis has been done on how, or even if, the probability can be manipulated by an attacker. Affects: Builds of dhcpd versions prior to version 4.4.1 when using BIND versions 9.11.2 or later, or BIND versions with specific bug fixes backported to them. ISC does not have access to comprehensive version lists for all repackagings of dhcpd that are vulnerable. In particular, builds from other vendors may also be affected. Operators are advised to consult their vendor documentation.
Affected products
-
- Version builds not wholly from ISC source < 4.4.1StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Multiple, non-ISC | Dhcpd | n/a |
|
Configuration 2
- 8.0
- 7.0
- 8.1
- 8.2
- 8.4
- 8.6
- 8.8
- 8.0
- 8.1_aarch64
- 8.2_aarch64
- 8.4_aarch64
- 8.6_aarch64
- 8.8_aarch64
- 7.0
- 8.0
- 8.1_s390x
- 8.2_s390x
- 8.4_s390x
- 8.6_s390x
- 8.8_s390x
- 7.0
- 7.0
- 8.0
- 8.1_ppc64le
- 8.2_ppc64le
- 8.4_ppc64le
- 8.6_ppc64le
- 8.8_ppc64le
- 7.0
- 7.0
- 8.2
- 8.4
- 8.6
- 8.1
- 8.2
- 8.4
- 8.6
- 8.8
- 8.2
- 8.4
- 8.6
- 8.8
- 8.1
- 8.2
- 8.4
- 8.6
- 8.8
- 7.0
No data.
Red Hat Enterprise Linux 7
dhcp-12:4.2.5-77.el7
Fixed · RHSA-2019:2060
Red Hat Enterprise Linux 8
dhcp-12:4.3.6-34.el8
Fixed · RHSA-2019:3525
Red Hat Enterprise Linux 5
dhcp
Not affected
Red Hat Enterprise Linux 6
dhcp
Out of support scope
Red Hat Virtualization 4
redhat-virtualization-host
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 7 | dhcp-12:4.2.5-77.el7 | Fixed | RHSA-2019:2060 |
| Red Hat Enterprise Linux 8 | dhcp-12:4.3.6-34.el8 | Fixed | RHSA-2019:3525 |
| Red Hat Enterprise Linux 5 | dhcp | Not affected | n/a |
| Red Hat Enterprise Linux 6 | dhcp | Out of support scope | n/a |
| Red Hat Virtualization 4 | redhat-virtualization-host | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
1 other source (CVE.org) ▾
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:H/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 (16 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 8.81% (0.08813) | 95.04th | v5 (v2026.06.15) |
| Jun 15, 2026 | 8.81% (0.08813) | 94.50th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.27% (0.00265) | 49.82th | v4 (v2025.03.14) |
| Nov 18, 2025 | 1.45% (0.01448) | 79.11th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.20% (0.00200) | 39.98th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.23% (0.00227) | 61.81th | v3 (v2023.03.01) |
| May 4, 2024 | 0.23% (0.00227) | 60.71th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.16% (0.00163) | 51.16th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.63% (0.01626) | 75.89th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.63% (0.01626) | 75.84th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.63% (0.01626) | 73.79th | v2 (v2022.01.01) |
| Feb 4, 2022 | 11.05% (0.11049) | 88.53th | v2 (v2022.01.01) |
| Feb 3, 2022 | 5.36% (0.05363) | 79.74th | v1 |
| Jan 6, 2022 | 5.36% (0.05363) | 79.54th | v1 |
| Sep 1, 2021 | 1.25% (0.01247) | 68.62th | v1 |
| Apr 14, 2021 | 1.25% (0.01247) | 0.00th | v1 |
References (9)
- https://access.redhat.com/errata/RHSA-2019:2060 x_refsource_CONFIRMThird Party Advisory
- https://access.redhat.com/errata/RHSA-2019:3525 vendor-advisoryx_refsource_REDHATThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2019-6470 Vendor Advisory
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=896122 x_refsource_CONFIRMExploitMailing ListThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1708641 Issue Tracking
- https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00048.html x_refsource_CONFIRMMailing ListThird Party Advisory
- https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00049.html x_refsource_CONFIRMMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2019-6470
- https://www.cve.org/CVERecord?id=CVE-2019-6470
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/errata/RHSA-2019:2060 | x_refsource_CONFIRMThird Party Advisory | |
| https://access.redhat.com/errata/RHSA-2019:3525 | vendor-advisoryx_refsource_REDHATThird Party Advisory | |
| https://access.redhat.com/security/cve/CVE-2019-6470 | Vendor Advisory | |
| https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=896122 | x_refsource_CONFIRMExploitMailing ListThird Party Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1708641 | Issue Tracking | |
| https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00048.html | x_refsource_CONFIRMMailing ListThird Party Advisory | |
| https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00049.html | x_refsource_CONFIRMMailing ListThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2019-6470 | ||
| https://www.cve.org/CVERecord?id=CVE-2019-6470 |
Change history (0)
No recorded changes yet.