{"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":"2026-11-06T19:14:06.068848074Z","published":"2016-04-29T00:18:22Z","database_specific":{"osv":"https://github.com/ocaml/security-advisories/tree/generated-osv/2016/OSEC-2016-01.json","human_link":"https://github.com/ocaml/security-advisories/tree/main/advisories/2016/OSEC-2016-01.md","cwe":["CWE-119","CWE-200"]},"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"}]}],"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"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ocaml/ocaml","events":[{"introduced":"0"},{"fixed":"659615c7b100a89eafe6253e7a5b9d84d0e8df74"}]}],"versions":["flambda_fork_point"],"database_specific":{"vanir_signatures_modified":"2026-11-06T19:14:06Z","source":"https://github.com/ocaml/security-advisories/blob/generated-osv/2016/OSEC-2016-01.json","vanir_signatures":[{"signature_type":"Line","signature_version":"v1","source":"https://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74","target":{"file":"byterun/alloc.c"},"deprecated":false,"digest":{"line_hashes":["297134581783518190232305096955709827343","86702773046983713261411000937503317436","175354524405815385958652428238171284707","225813051060905969896847126940363767535","80947609156901628575749315377655207158","234546213613500856380613242533067117431","319675424272689619655773296571607687751","42618432546425227918416254476888121732"],"threshold":0.9},"id":"OSEC-2016-01-39872619"},{"digest":{"threshold":0.9,"line_hashes":["10052243845623888550354841528198123243","313133952579991044620704436137614753717","266752456972937092085304220901563235122","159846084899688354175353893237558839589"]},"id":"OSEC-2016-01-7919b3a3","signature_type":"Line","signature_version":"v1","source":"https://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74","target":{"file":"byterun/intern.c"},"deprecated":false},{"source":"https://github.com/ocaml/ocaml/commit/659615c7b100a89eafe6253e7a5b9d84d0e8df74","target":{"file":"byterun/str.c"},"deprecated":false,"digest":{"line_hashes":["85424996336434796955035671983631143266","85551395679935241665303117152812282284","326958492464927746833064612802261356257","207772007117946504258662421451366370432","264253471812095600845252695062925757703","270191134296166034732436902130702877891","189680050811112729297100476753550978281","226231212319695106505871185064014352418"],"threshold":0.9},"id":"OSEC-2016-01-d7e7e855","signature_type":"Line","signature_version":"v1"}]}}],"schema_version":"1.9.2","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"}]}