Security Experts:

Connect with us

Hi, what are you looking for?



BIND Updates Patch High-Severity, Remotely Exploitable DoS Flaws

The latest BIND updates patch multiple remotely exploitable vulnerabilities that could lead to denial-of-service (DoS).

The Internet Systems Consortium (ISC) this week announced patches for multiple high-severity denial-of-service (DoS) vulnerabilities in the DNS software suite BIND.

The addressed issues could be exploited remotely to cause named – the BIND daemon that acts both as an authoritative name server and as a recursive resolver – to crash, or could lead to the exhaustion of the available memory.

The first of the security defects, tracked as CVE-2022-3094, can be exploited by sending a flood of dynamic DNS updates, which would cause named to allocate large amounts of memory, resulting in a crash due to a lack of free memory.

According to ISC, because allocated memory is only retained for clients for which access credentials are accepted, the scope of the vulnerability is limited to trusted clients that are allowed to make dynamic zone changes.

For BIND 9.11 and earlier branches, the flaw can be exploited to exhaust internal resources, which results in performance issues, but not a crash.

Tracked as CVE-2022-3736, the second issue leads to a crash “when stale cache and stale answers are enabled, option stale-answer-client-timeout is set to a positive integer, and the resolver receives an RRSIG query,” ISC explains. A remote attacker can trigger the bug by sending crafted queries to the resolver.

The third vulnerability, CVE-2022-3924, impacts the implementation of the stale-answer-client-timeout option, when the resolver receives too many queries that require recursion. If the number of clients waiting for recursion to complete is high enough, a race may occur between providing a stale answer to the longest waiting client and sending an early timeout SERVFAIL, causing named to crash.

All three vulnerabilities were resolved with the release of BIND versions 9.16.37, 9.18.11, and 9.19.9. ISC says it is not aware of any of these vulnerabilities being exploited, but encourages all users to update their BIND installations as soon as possible.

ISC also warns of CVE-2022-3488, a bug impacting all supported BIND preview edition versions (a special feature preview branch provided to eligible customers).

The issue can be triggered by sending two responses in quick succession from the same nameserver, both ECS pseudo-options, but with the first response broken, causing the resolver to reject the query response. When processing the second response, named crashes.

BIND preview edition version 9.16.37-S1 resolves all four security defects. Additional information on the addressed vulnerabilities can be found in the BIND 9 security vulnerability matrix.

Related: BIND Updates Patch High-Severity Vulnerabilities

Related: High-Severity Vulnerabilities Patched in BIND Server

Related: High-Severity DoS Vulnerability Patched in BIND DNS Software

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...


Apple has released updates for macOS, iOS and Safari and they all include a WebKit patch for a zero-day vulnerability tracked as CVE-2023-23529.

Application Security

Drupal released updates that resolve four vulnerabilities in Drupal core and three plugins.

Cloud Security

VMware vRealize Log Insight vulnerability allows an unauthenticated attacker to take full control of a target system.

IoT Security

Lexmark warns of a remote code execution (RCE) vulnerability impacting over 120 printer models, for which PoC code has been published.

Application Security

A CSRF vulnerability in the source control management (SCM) service Kudu could be exploited to achieve remote code execution in multiple Azure services.


Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.