CriticalFix available
newlib, picolibc — security advisory
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.
- Products
- newlib, picolibc
- Affected versions
- 3.3.0-1.3
- Fixed versions
- 1.5-1, 3.3.0-1.3+deb12u1, 4.4.0.20231231-2
- CVEs
- CVE-2021-3420
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:35 UTC · Revision 1
Source evidence
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.
osv:DEBIAN-CVE-2021-3420
newlib
Fixed versions: 3.3.0-1.3+deb12u1
newlib
Fixed versions: 4.4.0.20231231-2
newlib
Fixed versions: 4.4.0.20231231-2
picolibc
Fixed versions: 1.5-1
picolibc
Fixed versions: 1.5-1
picolibc
Fixed versions: 1.5-1
Complete source record
{
"id": "295b8ef8eceba44d16e4362c5589e8376d21820f85877b50c010279de2c1e1f4",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-3420",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-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.",
"evidence": "osv:DEBIAN-CVE-2021-3420",
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{
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"package": {
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"package": {
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"ecosystem_specific": {
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}
}
],
"modified": "2026-10-23T18:03:27.667852985Z",
"provider": "osv",
"upstream": [
"CVE-2021-3420"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-3420"
]
},
"related_cves": [
{
"value": "CVE-2021-3420",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 421574,
"published_at": "2021-03-05T21:15:13.437+00:00"
}