{"id":"CVE-2023-26438","aliases":["EUVD-2023-30258","GHSA-cp3q-q6mx-w79j"],"status":"published","title":"External service lookups for a number of protocols were vulnerable to a time-of-check/time-of-use...","description":"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 known.","severity":{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.006,"percentile":0.48987,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-367","CWE-918"],"published":"2023-08-02T12:22:59Z","modified":"2026-06-17T05:43:20Z","products":[{"vendor":"open-xchange","product":"open-xchange_appsuite_backend"},{"vendor":"open-xchange gmbh","product":"ox app suite"},{"vendor":"ox software gmbh","product":"ox app suite"}],"references":[{"url":"https://software.open-xchange.com/products/appsuite/doc/Release_Notes_for_Patch_Release_6230_7.10.6_2023-05-02.pdf","tags":["release-notes","x_transferred","Release Notes"]},{"url":"https://documentation.open-xchange.com/appsuite/security/advisories/csaf/2023/oxas-adv-2023-0003.json","tags":["vendor-advisory","x_transferred"]},{"url":"http://seclists.org/fulldisclosure/2023/Aug/8","tags":["x_transferred","Mailing List","Third Party Advisory"]},{"url":"http://packetstormsecurity.com/files/173943/OX-App-Suite-SSRF-SQL-Injection-Cross-Site-Scripting.html","tags":["x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-26438"},{"url":"https://documentation.open-xchange.com/security/advisories/csaf/oxas-adv-2023-0003.json"},{"url":"https://github.com/advisories/GHSA-cp3q-q6mx-w79j"}],"sources":{"cve":[{"id":"CVE-2023-26438","description":"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 known.\n\n","status":"published","published":"2023-08-02T12:22:59.459Z","modified":"2024-08-02T11:46:24.656Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:35:15.434947Z"}],"euvd":[{"id":"EUVD-2023-30258","description":"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 known.\n\n","status":"published","published":"2023-08-02T12:22:59Z","modified":"2024-08-02T11:46:24Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T03:50:06.766939Z"}],"ghsa":[{"id":"GHSA-cp3q-q6mx-w79j","title":"External service lookups for a number of protocols were vulnerable to a time-of-check/time-of-use...","description":"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 known.\n\n","status":"published","published":"2023-08-02T15:30:52Z","modified":"2024-01-21T05:06:03Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-367","CWE-918"],"updated_at":"2026-11-02T14:55:27.854531Z"}],"nvd":[{"id":"CVE-2023-26438","description":"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 known.\n\n","status":"published","published":"2023-08-02T13:15:10.323Z","modified":"2026-06-17T05:43:20.15Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":3.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","level":"low","assessor":"primary"}],"cwes":["CWE-918","CWE-367"],"updated_at":"2026-11-02T14:08:20.798312Z"}]}}