{"id":"CVE-2021-33641","aliases":["CLSA-2026-1782221814","EUVD-2021-20318","GHSA-56c6-2pfc-9rvh","OESA-2023-1033"],"status":"published","title":"When processing files, malloc stores the data of the current line. When processing comments,...","description":"When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.00278,"percentile":0.20338,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-416"],"published":"2023-01-13T11:05:30Z","modified":"2026-10-26T09:30:20Z","fixes":[{"ecosystem":"TuxCare:AlmaLinux:9.2","package":"byacc","fixed_in":["2.0.20210109-4.el9.tuxcare.els1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"TuxCare:AlmaLinux:9.2","package":"byacc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.20210109-4.el9.tuxcare.els1"}]}]},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP1","package":"byacc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.20200330-2.oe1"}]}],"bundled":2},{"source":"osv","ecosystem":"openEuler:20.03-LTS-SP3","package":"byacc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.20200330-2.oe1"}]}],"bundled":2},{"source":"osv","ecosystem":"openEuler:22.03-LTS","package":"byacc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.20210808-4.oe2203sp1"}]}],"bundled":2},{"source":"osv","ecosystem":"openEuler:22.03-LTS-SP1","package":"byacc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.0.20210808-4.oe2203sp1"}]}],"bundled":2}],"products":[{"vendor":"openeuler","product":"byacc"}],"references":[{"url":"https://gitee.com/src-openeuler/byacc/commit/50225f48c6b53e9d7c936681a06682404cb8ec4d","tags":["x_transferred","Permissions Required","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33641","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-56c6-2pfc-9rvh"},{"url":"https://errata.tuxcare.com/els_os/almalinux9.2esu/CLSA-2026-1782221814.html","tags":["advisory"]},{"url":"https://www.openeuler.org/en/security/safety-bulletin/detail.html?id=openEuler-SA-2023-1033","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-33642","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2021-33641","description":"When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).","status":"published","published":"2023-01-20T00:00:00Z","modified":"2025-04-03T20:03:08.779Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:33:10.204494Z"}],"euvd":[{"id":"EUVD-2021-20318","description":"When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).","status":"published","published":"2023-01-20T00:00:00Z","modified":"2025-04-03T20:03:08Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T20:52:42.939917Z"}],"ghsa":[{"id":"GHSA-56c6-2pfc-9rvh","title":"When processing files, malloc stores the data of the current line. When processing comments,...","description":"When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).","status":"published","published":"2023-01-20T21:30:26Z","modified":"2023-02-14T05:06:30Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:54:07.544087Z"}],"nvd":[{"id":"CVE-2021-33641","description":"When processing files, malloc stores the data of the current line. When processing comments, malloc incorrectly accesses the released memory (use after free).","status":"published","published":"2023-01-20T21:15:10.803Z","modified":"2026-06-17T03:54:55.34Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-416"],"updated_at":"2026-11-02T14:07:07.323379Z"}],"osv":[{"id":"OESA-2023-1033","title":"byacc security update","description":"Berkeley Yacc is an LALR(1) parser generator.  Berkeley Yacc has been made as compatible as possible with AT\u0026amp;T Yacc.  Berkeley Yacc can accept any input specification that conforms to the AT\u0026amp;T Yacc documentation.  Specifications that take advantage of undocumented features of AT\u0026amp;T Yacc will probably be rejected.\r\n\r\nSecurity Fix(es):\r\n\r\nNo description is available for this CVE.(CVE-2021-33641)\r\n\r\nNo description is available for this CVE.(CVE-2021-33642)","status":"published","published":"2023-01-13T11:05:30Z","modified":"2026-08-18T01:17:28.701091274Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:52:39.934788Z"},{"id":"CLSA-2026-1782221814","title":"byacc: Fix of CVE-2021-33641","description":"- CVE-2021-33641: fix use-after-free in more_curly() in reader.c","status":"published","published":"2026-06-23T13:37:09Z","modified":"2026-10-26T09:30:20.80843279Z","updated_at":"2026-11-02T15:43:45.794021Z"}]}}