{"id":"OSEC-2016-01","summary":"Buffer overflow and information leak in OCaml \u003c 4.03.0","details":"## Bug description\n\nOCaml versions 4.02.3 and earlier have a runtime bug that, on 64-bit platforms, causes sizes arguments to an internal memmove call to be sign-extended from 32 to 64-bits before being passed to the memmove function.\n\nThis leads arguments between 2GiB and 4GiB to be interpreted as larger than they are (specifically, a bit below 2^64), causing a buffer overflow.\n\nArguments between 4GiB and 6GiB are interpreted as 4GiB smaller than they should be, causing a possible information leak.\n\nThis commit fixes the bug:\nhttps://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74#diff-a97df53e3ebc59bb457191b496c90762\nThe function caml_bit_string is called indirectly from such functions as String.copy. String.copy for instance is supposed to be a \"safe\" function for which OCaml's memory safety guarantees apply.","aliases":["CVE-2015-8869"],"modified":"2026-02-17T00:26:51.542995Z","published":"2016-04-29T00:18:22Z","database_specific":{"cwe":["CWE-119","CWE-200"],"human_link":"https://github.com/ocaml/security-advisories/tree/main/advisories/2016/OSEC-2016-01.md","osv":"https://github.com/ocaml/security-advisories/tree/generated-osv/2016/OSEC-2016-01.json"},"references":[{"type":"REPORT","url":"https://github.com/ocaml/ocaml/issues/7003"}],"affected":[{"package":{"name":"ocaml","ecosystem":"opam","purl":"pkg:opam/ocaml"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.03.0"}]},{"type":"GIT","repo":"https://github.com/ocaml/ocaml","events":[{"introduced":"0"},{"fixed":"659615c7b100a89eafe6253e7a5b9d84d0e8df74"}]}],"versions":["3.07","3.07+1","3.07+2","3.08.0","3.08.1","3.08.2","3.08.3","3.08.4","3.09.0","3.09.1","3.09.2","3.09.3","3.10.0","3.10.1","3.10.2","3.11.0","3.11.1","3.11.2","3.12.0","3.12.1","4.00.0","4.00.1","4.01.0","4.02.0","4.02.1","4.02.2","4.02.3","4.02.4"],"ecosystem_specific":{"opam_constraint":"ocaml {\u003c \"4.03.0\"}"},"database_specific":{"source":"https://github.com/ocaml/security-advisories/blob/generated-osv/2016/OSEC-2016-01.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"}],"credits":[{"name":"Radek Micek","type":"REPORTER"},{"name":"Damien Doligez","type":"REMEDIATION_DEVELOPER"}]}