CVE-2021-3420
A flaw was found in newlib in versions prior to 4.0.0. Improper overflow validation in the memory...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
9.8
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.
- Record
CVE-2021-3420- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-190
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-3420- Weakness
- CWE-190
- Updated
- 2026-11-02
EUVDEUVD-2021-26748 No score
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.
- Record
EUVD-2021-26748- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-wp32-4vw5-mw9c No score
A flaw was found in newlib in versions prior to 4.0.0. Improper overflow validation in the memory...
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.
- Record
GHSA-wp32-4vw5-mw9c- Weakness
- CWE-120
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-3420
9.8
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.
- Record
ALPINE-CVE-2021-3420- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
OSV
9.8
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.
- Record
CVE-2021-3420- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-3420
9.8
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.
- Record
DEBIAN-CVE-2021-3420- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-3420
9.8
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.
- Record
UBUNTU-CVE-2021-3420- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11086-1 No score
newlib-4.1.0-2.2 on GA media
These are all security issues fixed in the newlib-4.1.0-2.2 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11086-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
newlibAlpine:v3.14 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.15 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.16 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.17 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.18 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.19 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.20 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.21 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.22 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibAlpine:v3.23 |
before 4.1.0-r0 | 4.1.0-r0 |
Show 13 moreShow less
| Package | Affected | Fixed |
|---|---|---|
newlibAlpine:v3.24 |
before 4.1.0-r0 | 4.1.0-r0 |
newlibDebian:12 |
before 3.3.0-1.3+deb12u1, plus listed versions 3.3.0-1.3 |
3.3.0-1.3+deb12u1 |
newlibDebian:13 |
before 4.4.0.20231231-2 | 4.4.0.20231231-2 |
newlibDebian:14 |
before 4.4.0.20231231-2 | 4.4.0.20231231-2 |
picolibcDebian:12 |
before 1.5-1 | 1.5-1 |
picolibcDebian:13 |
before 1.5-1 | 1.5-1 |
picolibcDebian:14 |
before 1.5-1 | 1.5-1 |
newlibUbuntu:16.04:LTS |
All versions, plus listed versions 2.1.0+git20141201.db59ff3-22.2.0+git20150830.5a3d536-1 |
None known |
newlibUbuntu:18.04:LTS |
All versions, plus listed versions 2.4.0.20160527-22.4.0.20160527-32.4.0.20160527-3ubuntu0.1 |
None known |
newlibUbuntu:20.04:LTS |
All versions, plus listed versions 3.1.0.20181231-13.3.0-0ubuntu1 |
None known |
newlibUbuntu:22.04:LTS |
All versions, plus listed versions 3.3.0-13.3.0-1.23.3.0-1.3 |
None known |
newlibUbuntu:24.04:LTS |
All versions, plus listed versions 3.3.0-1.34.4.0.20231231-2 |
None known |
newlibopenSUSE:Tumbleweed |
before 4.1.0-2.2 | 4.1.0-2.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3420 is a critical vulnerability (CVSS 9.8) in Newlib Project Newlib, published March 5, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.10%, the 81st percentile. Fixed in newlib 4.1.0-r0.
References
bugzilla.redhat.com/show_bug.cgi?id=1934088
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEBF6YHWFNCBW5A2ENSQ3Z56ELF4MTRE
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LSQZEUANAWBBAOC4TF5PTPJVLMUR7SFD
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AMK54N6UOPBFFX2YT32TWSAEFTHGSKAA
nvd.nist.gov/vuln/detail/CVE-2021-3420
lists.fedoraproject.org/archives/list/[email protected]/message/AEBF6YHWFNCBW5A2ENSQ3Z56ELF4MTRE
Show 9 moreShow less
lists.fedoraproject.org/archives/list/[email protected]/message/AMK54N6UOPBFFX2YT32TWSAEFTHGSKAA
lists.fedoraproject.org/archives/list/[email protected]/message/LSQZEUANAWBBAOC4TF5PTPJVLMUR7SFD
github.com/advisories/GHSA-wp32-4vw5-mw9c
security.alpinelinux.org/vuln/CVE-2021-3420
security-tracker.debian.org/tracker/CVE-2021-3420
ubuntu.com/security/CVE-2021-3420
sourceware.org/git?p=newlib-cygwin.git;a=commit;h=aa106b29a6a8a1b0df9e334704292cbc32f2d44e
cve.org/CVERecord?id=CVE-2021-3420
suse.com/security/cve/CVE-2021-3420