Summary
USN-7836-1 fixed vulnerabilities in Bind. This update provides the
corresponding fixes for Ubuntu 20.04 LTS.
Original advisory details:
Zuyao Xu and Xiang Li discovered that Bind incorrectly handled certain
malformed DNSKEY records. A remote attacker could possibly use this issue
to cause Bind to consume resources, resulting in a denial of service.
(CVE-2025-8677)
Yuxiao Wu, Yunyi Zhang, Baojun Liu, and Haixin Duan discovered that Bind
incorrectly accepted certain records from answers. A remote attacker could
possibly use this issue to perform a cache poisoning attack.
(CVE-2025-40778)
Amit Klein and Omer Ben Simhon discovered that Bind used a weak PRNG. A
remote attacker could possibly use this issue to perform a cache poisoning
attack. (CVE-2025-40780)
Fixed packages 1
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | bind9 | 1:9.18.30-0ubuntu0.20.04.2+esm1 |
Vulnerabilities 3
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High 8.6CVE-2025-40778 Public exploit
Cache poisoning attacks with unsolicited RRs
Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 …
-
High 8.6
Cache poisoning due to weak PRNG
In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.…
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High 7.5CVE-2025-8677 EPSS 11%
Resource exhaustion via malformed DNSKEY handling
Querying for records within a specially crafted zone containing certain malformed DNSKEY records can lead to CPU exhaustion. This issue affects BIND 9 versions 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.18.11-S1 through 9.18.39-…