CVE-2021-30151

Exp

Sidekiq through 5.1.3 and 6.x through 6.2.0 allows XSS via the queue name of the live-poll feature when Internet Explorer is used.

Published: 2021-04-06 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-30151 is rated High Exploit Risk (65.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 4.16%). 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-2021-30151

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

Exploit prediction scoring system (EPSS) score for CVE-2021-30151

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 13.90% 4.16% -9.74%
2 2026-05-31 14.88% 13.90% -0.98%
3 2026-05-13 — 14.88% —

Full EPSS history (61 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-30151

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-30151

GitHub Security Advisory for CVE-2021-30151

GHSA-grh7-935j-hg6w · Severity: medium · Ecosystem: rubygems — Cross-site Scripting in Sidekiq

OS Trackers for CVE-2021-30151

vendor priority summary link
debian not yet assigned CVE-2021-30151 not yet assigned priority: Debian including 1 source packages (ruby-sidekiq), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-30151
redhat medium — https://access.redhat.com/security/cve/CVE-2021-30151
ubuntu medium CVE-2021-30151 medium priority: Ubuntu including 1 source packages (ruby-sidekiq), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 7, not-affected 4, released 3, DNE 1, needed 1. https://ubuntu.com/security/CVE-2021-30151

Affected software / configurations for CVE-2021-30151

Vendor Product Version Raw CPE
contribsys sidekiq <= 5.1.3 cpe:2.3:a:contribsys:sidekiq:*:*:*:*:*:*:*:*
contribsys sidekiq >= 6.0.0, <= 6.2.0 cpe:2.3:a:contribsys:sidekiq:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2021-30151

cvelogic Threat Intelligence