{"id":"CVE-2021-27645","title":"The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Servi…","summary":"The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Servi…","severity":"low","cvss":2.5,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-415","CWE-415"],"vendor":"gnu","product":"glibc","affected":["glibc >= 2.29, <= 2.33","fedora = 33","fedora = 34","debian_linux = 10.0"],"published":"2021-02-24","updated":"2026-10-14","sourceUpdated":"2026-10-14T12:17:10.460","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-27645","references":[{"url":"https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/","label":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/","label":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202107-07","label":"cve@mitre.org"},{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=27462","label":"cve@mitre.org"},{"url":"https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202107-07","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://sourceware.org/bugzilla/show_bug.cgi?id=27462","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-831302.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.00374,"epssPercentile":0.29534,"ingestedAt":"2026-10-14T12:29:10.816Z","slug":"CVE-2021-27645","body":"## Overview\n\nThe nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.\n\n## Affected\n\n- `glibc >= 2.29, <= 2.33`\n- `fedora = 33`\n- `fedora = 34`\n- `debian_linux = 10.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":14,"depthScoreParts":{"impact":13.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}