{"cve":"CVE-2023-38545","nvd":{"published":"2023-10-18T04:15:11.077","modified":"2026-06-17T06:10:41.627","status":"Modified","description":"This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy\nhandshake.\n\nWhen curl is asked to pass along the host name to the SOCKS5 proxy to allow\nthat to resolve the address instead of it getting done by curl itself, the\nmaximum length that host name can be is 255 bytes.\n\nIf the host name is detected to be longer, curl switches to local name\nresolving and instead passes on the resolved address only. Due to this bug,\nthe local variable that means \"let the host resolve the name\" could get the\nwrong value during a slow SOCKS5 handshake, and contrary to the intention,\ncopy the too long host name to the target buffer instead of copying just the\nresolved address there.\n\nThe target buffer being a heap based buffer, and the host name coming from the\nURL that curl has been told to operate with.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-787"],"references":["http://seclists.org/fulldisclosure/2024/Jan/34","http://seclists.org/fulldisclosure/2024/Jan/37","http://seclists.org/fulldisclosure/2024/Jan/38","https://curl.se/docs/CVE-2023-38545.html","https://forum.vmssoftware.com/viewtopic.php?f=8&t=8868"],"products":["fedoraproject:fedora","haxx:libcurl","microsoft:windows_10_1809","microsoft:windows_10_21h2","microsoft:windows_10_22h2","microsoft:windows_11_21h2","microsoft:windows_11_22h2","microsoft:windows_11_23h2","microsoft:windows_server_2019","microsoft:windows_server_2022","netapp:active_iq_unified_manager","netapp:oncommand_insight","netapp:oncommand_workflow_automation"],"source":"nvd","synced_at":"2026-10-19T21:40:11.519948003+00:00"},"epss":{"cve":"CVE-2023-38545","score":0.78689,"percentile":0.99588,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}