CVE-2020-14966

Exp

An issue was discovered in the jsrsasign package through 8.0.18 for Node.js. It allows a malleability in ECDSA signatures by not checking overflows in the length of a sequence and '0' characters appended or prepended to an integer. The modified signatures are verified as valid. This could have a security-relevant impact if an application relied on a single canonical signature.

Published: 2020-06-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-14966 is rated High Exploit Risk (67.4/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.12%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2020-14966

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-14966

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 2026-06-15 0.28% 1.12% +0.84%
2 2025-11-21 0.25% 0.28% +0.03%
3 2025-11-18 — 0.25% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-14966

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:H/A:N 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:N 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:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-14966

GitHub Security Advisory for CVE-2020-14966

GHSA-p8c3-7rj8-q963 · Severity: high · Ecosystem: npm — ECDSA signature validation vulnerability by accepting wrong ASN.1 encoding in jsrsasign

Affected software / configurations for CVE-2020-14966

Vendor Product Version Raw CPE
jsrsasign_project jsrsasign <= 8.0.18 cpe:2.3:a:jsrsasign_project:jsrsasign:*:*:*:*:*:node.js:*:*
netapp max_data — cpe:2.3:a:netapp:max_data:-:*:*:*:*:*:*:*

References for CVE-2020-14966

URL Tags
https://github.com/kjur/jsrsasign/issues/437 Exploit Issue Tracking Third Party Advisory
https://github.com/kjur/jsrsasign/releases/tag/8.0.17 Release Notes Third Party Advisory
https://github.com/kjur/jsrsasign/releases/tag/8.0.18 Release Notes Third Party Advisory
https://kjur.github.io/jsrsasign/ Release Notes Third Party Advisory
https://security.netapp.com/advisory/ntap-20200724-0001/ Third Party Advisory
https://www.npmjs.com/package/jsrsasign Product Third Party Advisory
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