CVE-2022-39202 | IRC mode parameter confusion in matrix-appservice-irc

matrix-appservice-irc is an open source Node.js IRC bridge for Matrix. The Internet Relay Chat (IRC) protocol allows you to specify multiple modes in a single mode command. Due to a bug in the underlying matrix-org/node-irc library, affected versions of matrix-appservice-irc perform parsing of such modes incorrectly, potentially resulting in the wrong user being given permissions. Mode commands can only be executed by privileged users, so this can only be abused if an operator is tricked into running the command on behalf of an attacker. The vulnerability has been patched in matrix-appservice-irc 0.35.0. As a workaround users should refrain from entering mode commands suggested by untrusted users. Avoid using multiple modes in a single command.

Published: 2022-09-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-39202 is rated Low Risk (34.6/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.27%). 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-2022-39202

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 2025-10-01 0.44% 0.27% -0.17%
2 2025-09-16 0.34% 0.44% +0.10%
3 2025-09-15 — 0.34% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-39202

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L 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:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 0.9 3.4 [email protected]
6.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L 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:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 3.4 [email protected]

Weakness enumeration for CVE-2022-39202

GitHub Security Advisory for CVE-2022-39202

GHSA-cq7q-5c67-w39w · Severity: medium · Ecosystem: npm — matrix-appservice-irc vulnerable to IRC mode parameter confusion

Affected software / configurations for CVE-2022-39202

Vendor Product Version Raw CPE
matrix matrix_irc_bridge < 0.35.0 cpe:2.3:a:matrix:matrix_irc_bridge:*:*:*:*:*:node.js:*:*

References for CVE-2022-39202

cvelogic Threat Intelligence