CVE-2021-29376

ircII before 20210314 allows remote attackers to cause a denial of service (segmentation fault and client crash, disconnecting the victim from an IRC server) via a crafted CTCP UTC message.

Published: 2021-03-30 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-29376 is rated Moderate Risk (60.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.62%). 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-2021-29376

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 2026-05-29 4.29% 3.62% -0.67%
2 2026-01-14 3.61% 4.29% +0.68%
3 2025-11-21 — 3.61% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29376

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-2021-29376

OS Trackers for CVE-2021-29376

vendor priority summary link
alpine high CVE-2021-29376: 1 source package rows (ircii); 11 state rows across 11 repos (3.10-main, 3.11-main, 3.12-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community, edge-main); fixed 9, open 2. https://security.alpinelinux.org/vuln/CVE-2021-29376
debian not yet assigned CVE-2021-29376 not yet assigned priority: Debian including 2 source packages (ircii, scrollz), 8 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 8. https://security-tracker.debian.org/tracker/CVE-2021-29376
ubuntu medium CVE-2021-29376 medium priority: Ubuntu including 1 source packages (ircii), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 7, DNE 1. https://ubuntu.com/security/CVE-2021-29376

Affected software / configurations for CVE-2021-29376

Vendor Product Version Raw CPE
eterna ircii < 20210314 cpe:2.3:a:eterna:ircii:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2021-29376

cvelogic Threat Intelligence