CVE-2021-30130

phpseclib before 2.0.31 and 3.x before 3.0.7 mishandles RSA PKCS#1 v1.5 signature verification.

Published: 2021-04-06 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-30130 is rated Moderate Risk (44.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.20%). Review affected assets and schedule remediation.

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-2021-30130

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 2026-05-11 0.43% 0.20% -0.22%
2 2026-04-29 0.60% 0.43% -0.17%
3 2026-01-18 — 0.60% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-30130

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-2021-30130

GitHub Security Advisory for CVE-2021-30130

GHSA-vf4w-fg7r-5v94 · Severity: high · Ecosystem: composer — Improper Certificate Validation in phpseclib

OS Trackers for CVE-2021-30130

vendor priority summary link
debian not yet assigned CVE-2021-30130 not yet assigned priority: Debian including 3 source packages (php-phpseclib, php-phpseclib3, phpseclib), 13 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 13. https://security-tracker.debian.org/tracker/CVE-2021-30130
ubuntu medium CVE-2021-30130 medium priority: Ubuntu including 3 source packages (php-phpseclib, php-phpseclib3, phpseclib), 39 status rows across 15 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): not-affected 16, ignored 15, released 4, DNE 3, needs-triage 1. https://ubuntu.com/security/CVE-2021-30130

Affected software / configurations for CVE-2021-30130

Vendor Product Version Raw CPE
phpseclib phpseclib < 2.0.31 cpe:2.3:a:phpseclib:phpseclib:*:*:*:*:*:*:*:*
phpseclib phpseclib >= 3.0, < 3.0.7 cpe:2.3:a:phpseclib:phpseclib:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2021-30130

cvelogic Threat Intelligence