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Vulnerability details: VCID-8dn8-f7r5-aaaa
Vulnerability ID VCID-8dn8-f7r5-aaaa
Aliases CVE-2021-27645
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 Service on the local system. This is related to netgroupcache.c.
Status Published
Exploitability 0.5
Weighted Severity 8.0
Risk 4.0
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-415 Double Free
CWE-416 Use After Free
System Score Found at
rhas Moderate https://access.redhat.com/errata/RHSA-2021:4358
cvssv3 2.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-27645.json
epss 0.00024 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
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epss 0.00026 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00026 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
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epss 0.00026 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
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epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.00047 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
epss 0.0005 https://api.first.org/data/v1/epss?cve=CVE-2021-27645
rhbs low https://bugzilla.redhat.com/show_bug.cgi?id=1932589
cvssv3.1 2.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3.1 2.5 https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
ssvc Track https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
cvssv3.1 2.5 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
ssvc Track https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
cvssv3.1 2.5 https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
ssvc Track https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
cvssv2 1.9 https://nvd.nist.gov/vuln/detail/CVE-2021-27645
cvssv3 2.5 https://nvd.nist.gov/vuln/detail/CVE-2021-27645
cvssv3.1 2.5 https://nvd.nist.gov/vuln/detail/CVE-2021-27645
archlinux High https://security.archlinux.org/AVG-1621
cvssv3.1 2.5 https://security.gentoo.org/glsa/202107-07
ssvc Track https://security.gentoo.org/glsa/202107-07
cvssv3.1 2.5 https://sourceware.org/bugzilla/show_bug.cgi?id=27462
ssvc Track https://sourceware.org/bugzilla/show_bug.cgi?id=27462
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-27645.json
https://api.first.org/data/v1/epss?cve=CVE-2021-27645
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-27645
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
https://security.gentoo.org/glsa/202107-07
https://sourceware.org/bugzilla/show_bug.cgi?id=27462
1932589 https://bugzilla.redhat.com/show_bug.cgi?id=1932589
983479 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=983479
AVG-1621 https://security.archlinux.org/AVG-1621
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
CVE-2021-27645 https://nvd.nist.gov/vuln/detail/CVE-2021-27645
RHSA-2021:4358 https://access.redhat.com/errata/RHSA-2021:4358
USN-5310-1 https://usn.ubuntu.com/5310-1/
No exploits are available.
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2021-27645.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-09T14:57:29Z/ Found at https://lists.debian.org/debian-lts-announce/2022/10/msg00021.html
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-09T14:57:29Z/ Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5/
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-09T14:57:29Z/ Found at https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS/
Vector: AV:L/AC:M/Au:N/C:N/I:N/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-27645
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://nvd.nist.gov/vuln/detail/CVE-2021-27645
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://nvd.nist.gov/vuln/detail/CVE-2021-27645
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://security.gentoo.org/glsa/202107-07
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-09T14:57:29Z/ Found at https://security.gentoo.org/glsa/202107-07
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L Found at https://sourceware.org/bugzilla/show_bug.cgi?id=27462
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-09T14:57:29Z/ Found at https://sourceware.org/bugzilla/show_bug.cgi?id=27462
Exploit Prediction Scoring System (EPSS)
Percentile 0.04868
EPSS Score 0.00024
Published At May 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
There are no relevant records.