CVE-2023-26438 (open-xchange_appsuite_backend)

External service lookups for a number of protocols were vulnerable to a time-of-check/time-of-use (TOCTOU) weakness, involving the JDK DNS cache. Attackers that were timing DNS cache expiry correctly were able to inject configuration that would bypass existing network deny-lists. Attackers could exploit this weakness to discover the existence of restricted network infrastructure and service availability. Improvements were made to include deny-lists not only during the check of the provided connection data, but also during use. No publicly available exploits are …

attackers availability bypass cache check configuration cve discover dns exploit external infrastructure inject jdk lists network network infrastructure protocols restricted service toctou vulnerable weakness