CVE-2019-6470
dhcpd: use-after-free error leads crash in IPv6 mode when using mismatched BIND libraries
- Published
- Updated
- Reserved
- Assigned by
- isc
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| iscCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Analyzed | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 8.8% · top 4.8% of all CVEs (5 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
- A use-after-free error in DHCPv6 processing when interfacing with newer BIND libraries leads to frequent crashes
Affected products
- affected builds not wholly from ISC source < 4.4.1
References (5)
- https://access.redhat.com/errata/RHSA-2019:2060 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00049.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://lists.opensuse.org/opensuse-security-announce/2019-10/msg00048.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=896122 (opens in a new tab)x_refsource_CONFIRMx_transferred
- RHSA-2019:3525 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2019-6470)Record last updated .