LiveActive security incident?Get immediate response
CVE Record

CVE-2021-3580: A flaw was found in the way nettle's RSA decryption functions handled specially crafted ciphertext.

A flaw was found in the way nettle's RSA decryption functions handled specially crafted ciphertext. An attacker could use this flaw to provide a manipulated ciphertext leading to application crash and denial of service.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-3580 is a denial-of-service flaw in nettle's RSA decryption handling. If an application uses affected nettle code and processes attacker-supplied ciphertext, a malformed input could crash that application. The bundle identifies nettle 3.7.3 and vendor advisories, but provides no CVSS score.

Executive priority

Treat as a medium operational resilience issue. Prioritize internet-facing or business-critical services that process untrusted encrypted input, then complete routine patching elsewhere. Evidence does not support emergency response for active exploitation.

Technical view

The issue is CWE-20 input validation in nettle RSA decryption functions when handling specially crafted ciphertext. The documented impact is application crash and denial of service, not data theft or code execution. The bundle names nettle 3.7.3 and downstream advisories from Debian, NetApp, and Gentoo.

Likely exposure

Exposure is most likely in Linux systems, appliances, or applications that link against affected nettle packages and perform RSA decryption on untrusted input. The bundle does not prove exposure for all nettle versions or all downstream products.

Exploitation context

The provided sources do not indicate active exploitation, and CISA KEV status is false. Practical risk depends on whether attacker-controlled ciphertext can reach nettle RSA decryption paths in exposed services or processing workflows.

Researcher notes

The source bundle is sparse: no CVSS vector, no confirmed fixed upstream version, and limited affected-version detail beyond nettle 3.7.3. Analysis should focus on reachability of nettle RSA decryption functions through trusted versus untrusted input paths.

Mitigation direction

  • Inventory systems and products using nettle, especially nettle 3.7.3.
  • Apply relevant vendor security updates from Debian, Gentoo, NetApp, or your platform vendor.
  • Check vendor advisories for exact fixed package versions and restart dependent services.
  • Reduce exposure where untrusted clients can trigger RSA decryption until updates are applied.

Validation and detection

  • Confirm installed nettle package versions against vendor advisory guidance.
  • Identify applications or appliances linking to nettle and handling untrusted cryptographic input.
  • Review crash logs for unexplained failures in RSA decryption paths.
  • Verify patched packages are deployed across base images, hosts, and bundled dependencies.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-20: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-3580 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/anettlenettle 3.7.3Listed
Weakness

CWE details

CWE-20

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.