Ubuntu Security Notice 4969-3 - USN-4969-1 fixed a vulnerability in DHCP. The package for Ubuntu 21.04 introduced a regression causing it to reject certain valid configuration files. This update fixes the problem. 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. Various other issues were also addressed.
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