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Vulnerability details: VCID-uen2-z7z5-zfaf
Vulnerability ID VCID-uen2-z7z5-zfaf
Aliases CVE-2021-3420
Summary A flaw was found in newlib in versions prior to 4.0.0. Improper overflow validation in the memory allocation functions mEMALIGn, pvALLOc, nano_memalign, nano_valloc, nano_pvalloc could case an integer overflow, leading to an allocation of a small buffer and then to a heap-based buffer overflow.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Weaknesses (0)
There are no known CWE.
System Score Found at
epss 0.00289 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00289 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00308 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
epss 0.00347 https://api.first.org/data/v1/epss?cve=CVE-2021-3420
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2021-3420
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2021-3420
archlinux Medium https://security.archlinux.org/AVG-1628
Reference id Reference type URL
https://api.first.org/data/v1/epss?cve=CVE-2021-3420
https://bugzilla.redhat.com/show_bug.cgi?id=1934088
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3420
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEBF6YHWFNCBW5A2ENSQ3Z56ELF4MTRE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AMK54N6UOPBFFX2YT32TWSAEFTHGSKAA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQZEUANAWBBAOC4TF5PTPJVLMUR7SFD/
984424 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=984424
AVG-1628 https://security.archlinux.org/AVG-1628
cpe:2.3:a:newlib_project:newlib:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:newlib_project:newlib:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
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-2021-3420 https://nvd.nist.gov/vuln/detail/CVE-2021-3420
No exploits are available.
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2021-3420
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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2021-3420
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
Exploit Prediction Scoring System (EPSS)
Percentile 0.52038
EPSS Score 0.00289
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:30:31.387526+00:00 Alpine Linux Importer Import https://secdb.alpinelinux.org/v3.22/community.json 37.0.0