CVE-2021-3580

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.

Published: 2021-08-05 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3580 is rated Low Risk (39.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.10%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3580

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-03 0.04% 0.10% +0.06%
2 2025-11-21 1.24% 0.04% -1.20%
3 2025-11-18 — 1.24% —

Full EPSS history (21 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3580

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-3580

OS Trackers for CVE-2021-3580

vendor priority summary link
alpine — CVE-2021-3580: 1 source package rows (nettle); 14 state rows across 9 repos (3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 6. https://security.alpinelinux.org/vuln/CVE-2021-3580
debian not yet assigned CVE-2021-3580 not yet assigned priority: Debian including 1 source packages (nettle), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3580
gentoo normal CVE-2021-3580: 1 GLSA(s) (202401-24), 1 atom(s) (dev-libs/nettle); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-3580
redhat medium — https://access.redhat.com/security/cve/CVE-2021-3580
suse high CVE-2021-3580 severity important: SUSE including 410 source package names (0.1.0:libhogweed4-3.4.1-4.18.1, 0.1.0:libnettle6-3.4.1-4.18.1, …), 726 product×package rows across 172 product lines (Container caasp/v4/389-ds, Container caasp/v4/busybox, … (172 product lines)): Fixed 570, Known Affected 136, Known Not Affected 20. https://www.suse.com/security/cve/CVE-2021-3580/
ubuntu medium CVE-2021-3580 medium priority: Ubuntu including 1 source packages (nettle), 10 status rows across 10 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, trusty, upstream, xenial): released 5, not-affected 3, ignored 2. https://ubuntu.com/security/CVE-2021-3580

Affected software / configurations for CVE-2021-3580

Vendor Product Version Raw CPE
nettle_project nettle < 3.7.3 cpe:2.3:a:nettle_project:nettle:*:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
netapp ontap_select_deploy_administration_utility — cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*

References for CVE-2021-3580

cvelogic Threat Intelligence