Description
In ISC DHCP 1.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1 a system with access to a DHCP server, sending DHCP packets crafted to include fqdn labels longer than 63 bytes, could eventually cause the server to run out of memory.
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 · Modified | 3.1 | Medium6.5 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.66% · top 48% of all CVEs (6 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
- The function fqdn_universe_decode() allocates buffer space for the contents of option 81 (fqdn) data received in a DHCP packet. The maximum length of a DNS label is 63 bytes. The function tests the length byte of each label contained in the fqdn; if it finds a label whose length byte value is larger than 63, it returns without dereferencing the buffer space. This will cause a memory leak. Affects In ISC DHCP 1.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1
- CWE-770 (opens in a new tab)All about CWE-770 and its CVEs
Affected products
What to do
Solution: Upgrade to the patched release most closely related to your current version of ISC DHCP. These can all be downloaded from https://www.isc.org/downloads. 4.4.3-P1 4.1-ESV-R16-P2
Workaround: As exploiting this vulnerability requires an attacker to send packets for an extended period of time, restarting servers periodically could be a viable workaround.
Exploitation: We are not aware of any active exploits.
References (6)
- https://kb.isc.org/docs/cve-2022-2929 (opens in a new tab)x_transferred
- [debian-lts-announce] 20221010 [SECURITY] [DLA 3146-1] isc-dhcp security update (opens in a new tab)mailing-listx_transferred
- FEDORA-2022-f5a45757df (opens in a new tab)vendor-advisoryx_transferred
- FEDORA-2022-9ca9a94e28 (opens in a new tab)vendor-advisoryx_transferred
- FEDORA-2022-c4f274a54f (opens in a new tab)vendor-advisoryx_transferred
- GLSA-202305-22 (opens in a new tab)vendor-advisoryx_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-2022-2929)Record last updated .