USN-7230-3: FRR regression

USN-7230-2 fixed vulnerabilities in FRR. Unfortunately, the fix for CVE-2024-55553 introduced a regression in RPKI support, causing FRR to stop processing RPKI updates after the first one, so routes were not revalidated when RPKI data changed. In Ubuntu 20.04 LTS, the BGP daemon also failed to start when the RPKI module was enabled. This update fixes the problem. We apologize for the inconvenience. Original advisory details: Iggy Frankovic discovered that FRR incorrectly handled certain BGP messages. A remote attacker could possibly use this issue to cause FRR to crash, resulting in a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2024-44070) It was discovered that FRR re-validated all routes in certain instances when the internal socket's buffer size overflowed. A remote attacker could possibly use this issue to impact the performance of FRR, resulting in a denial of service. (CVE-2024-55553)