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OpenAdvisories
High USN-4969-1 1 CVE

isc-dhcp vulnerability

Published May 27, 2021 · Updated Apr 22, 2026

Ecosystem: Ubuntu

Summary

Jon Franklin and Pawel Wieczorkiewicz discovered that DHCP incorrectly
handled lease file parsing. A remote attacker could possibly use this issue
to cause DHCP to crash, resulting in a denial of service.

Fixed packages 2

ReleasePackageFixed in
Ubuntu · 18.04 LTS 18.04:LTS isc-dhcp 4.3.5-3ubuntu7.3
Ubuntu · 20.04 LTS 20.04:LTS isc-dhcp 4.4.1-2.1ubuntu5.20.04.2

Vulnerabilities 1

  • High 7.4
    CVE-2021-25217

    A buffer overrun in lease file parsing code can be used to exploit a common vulnerability shared by dhcpd and dhclient

    In ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16, ISC DHCP 4.4.0 -> 4.4.2 (Other branches of ISC DHCP (i.e., releases in the 4.0.x series or lower and releases in the 4.3.x series) are beyond their End-of-Life (EOL) and no longer supported by ISC. From inspection it is …

    ISC ISC DHCP isc-dhcp isc-dhcp Debian Ubuntu Azure Linux Alpine

References

  • report
    https://ubuntu.com/security/CVE-2021-25217