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CVE-2021-27645

15
FAUCET Score

CVE-2021-27645 is a double-free vulnerability in the nameserver caching daemon (nscd) of GNU C Library (glibc) versions 2.29 through 2.33, affecting various Debian, Fedora, and GNU systems. This flaw can lead to a crash of the nscd service, potentially causing a Denial of Service on the local system. With a CVSS score of 2.5 (LOW), it requires local access and high attack complexity, resulting in a low impact on availability. There is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this vulnerability.

Impacted Technologies

VendorProductVersion(s)CPE
>= 2.29, <= 2.33CPE matchmatch criteria
cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
10.0CPE matchmatch criteria
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

2.5LOW

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
LOW
Exploitability Score
1.0
Impact Score
1.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.37%
Probability of exploitation in next 30 days
EPSS Percentile
30.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0037 is in the 87th percentile among its peer group of 223 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (7)

redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 8Fixed in: glibc-0:2.28-164.el8
View patch
cephvendor investigatingvia llm_extracted
d-linkvendor investigatingvia llm_extracted
humansignalvendor investigatingvia llm_extracted
hyperledgervendor investigatingvia llm_extracted
m2teamvendor investigatingvia llm_extracted
roundcubevendor investigatingvia llm_extracted

Vendor Advisories (7)

cephllm-ceph-757e29f49fd4489eCRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
hyperledgerllm-hyperledger-3131efc9fc3bed9eCRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
roundcubellm-roundcube-8900788926ebda25CRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
m2teamllm-m2team-41bf9cb22f24a510CRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
humansignalllm-humansignal-a731b4173ec8e579CRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
d-linkllm-d-link-1b06970e59fff350CRITICAL

Multiple ctrlX CORE vulnerabilities

Apr 20, 2022
redhatCVE-2021-27645Low

glibc: Use-after-free in addgetnetgrentX function in netgroupcache.c

Feb 24, 2021

References

lists.debian.org / debian-lts-announce/2022/10/msg00021.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/7LZNT6KTMCCWPWXEOGSHD3YLYZKUGMH5
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/I7TS26LIZSOBLGJEZMJX4PXT5BQDE2WS
security.gentoo.org / glsa/202107-07
Third Party Advisory
sourceware.org / bugzilla/show_bug.cgi
Issue TrackingPatchThird Party Advisory