CISA Warns of Exploitable Vulnerabilities in Popular BIND 9 DNS Software

The Internet Systems Consortium (ISC) has released patches to address multiple security vulnerabilities in the Berkeley Internet Name Domain (BIND) 9 Domain Name System (DNS) software suite that could be exploited to trigger a denial-of-service (DoS) condition.

“A cyber threat actor could exploit one of these vulnerabilities to cause a denial-of-service condition,” the U.S. Cybersecurity and Infrastructure Security Agency (CISA) said in an advisory.

The list of four vulnerabilities is listed below -

• CVE-2024-4076 (CVSS score: 7.5) - Due to a logic error, lookups that triggered serving stale data and required lookups in local authoritative zone data could have resulted in an assertion failure
• CVE-2024-1975 (CVSS score: 7.5) - Validating DNS messages signed using the SIG(0) protocol could cause excessive CPU load, leading to a denial-of-service condition.
• CVE-2024-1737 (CVSS score: 7.5) - It is possible to craft excessively large numbers of resource record types for a given owner name, which has the effect of slowing down database processing
• CVE-2024-0760 (CVSS score: 7.5) - A malicious DNS client that sent many queries over TCP but never read the responses could cause a server to respond slowly or not at all for other clients

Successful exploitation of the aforementioned bugs could cause a named instance to terminate unexpectedly, deplete available CPU resources, slow down query processing by a factor of 100, and render the server unresponsive.

The flaws have been addressed in BIND 9 versions 9.18.28, 9.20.0, and 9.18.28-S1 released earlier this month. There is no evidence that any of the shortcomings have been exploited in the wild.

The disclosure comes months after the ISC addressed another flaw in BIND 9 called KeyTrap (CVE-2023-50387, CVSS score: 7.5) that could be abused to exhaust CPU resources and stall DNS resolvers, resulting in a denial-of-service (DoS).

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