Description
dhcpd in ISC DHCP 4.x before 4.2.3-P1 and 4.1-ESV before 4.1-ESV-R4 does not properly handle regular expressions in dhcpd.conf, which allows remote attackers to cause a denial of service (daemon crash) via a crafted request packet.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | isc-dhcp | 4.2.2.dfsg.1-5 | — |
| Debian 12 | isc-dhcp | 4.2.2.dfsg.1-5 | — |
| Debian 6.0 | isc-dhcp | 4.1.1-P1-15+squeeze5 | DSA-2519-2, DSA-2519-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | dhcp +3 | 12:4.1.1-25.P1.el6_2.1 | RHSA-2011:1819 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dhcp | 4.3.3.P1-3.1 | openSUSE-SU-2024:10358-1 |
Advisories 4
- RHSA-2011:1819 Red Hat Security Advisory: dhcp security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-2519-1 isc-dhcp - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2519-2 isc-dhcp - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10358-1 dhcp-4.3.3.P1-3.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- MDVSA-2011:182 vendor-advisory
- 47153 third-party-advisory
- FEDORA-2011-16976 vendor-advisory
- USN-1309-1 vendor-advisory
- openSUSE-SU-2011:1318 vendor-advisory
- isc-dhcp-dhcpd-regex-dos(71680) vdb-entry
- 47178 third-party-advisory
- https://www.isc.org/software/dhcp/advisories/cve-2011-4539
- FEDORA-2011-16981 vendor-advisory
- DSA-2519 vendor-advisory
- 1026393 vdb-entry
- GLSA-201301-06 vendor-advisory
- 50971 vdb-entry