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CVE-2024-39691 Xxe

Remediate Within 6 Months

CVE Information

Original CVE data


matrix-appservice-irc is a Node.js IRC bridge for the Matrix messaging protocol. The fix for GHSA-wm4w-7h2q-3pf7 / CVE-2024-32000 included in matrix-appservice-irc 2.0.0 relied on the Matrix homeserver-provided timestamp to determine whether a user has access to the event they're replying to when determining whether or not to include a truncated version of the original event in the IRC message. Since this value is controlled by external entities, a malicious Matrix homeserver joined to a room in which a matrix-appservice-irc bridge instance (before version 2.0.1) is present can fabricate the timestamp with the intent of tricking the bridge into leaking room messages the homeserver should not have access to. matrix-appservice-irc 2.0.1 drops the reliance on `origin_server_ts` when determining whether or not an event should be visible to a user, instead tracking the event timestamps internally. As a workaround, it's possible to limit the amount of information leaked by setting a reply template that doesn't contain the original message.

CVSS v2-
CVSS v3-
Affected Vendors

Basic Analysis

Common vulnerability metrics

Vulnerabilty type as detected by PRIOnengine


CVSS Scores as calculated by PRIOnengine
CVSS v24
CVSS v35.3



No exploit code is reported to exist.

Active Exploitation

Vulnerability is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. See the KEV Catalog

Social Network Activity


Threat Actor Activity

No sightings of the vulnerability within threat reports.

Cybersecurity Frameworks

How the vulnerability maps against various cybersecurity frameworks


Compliance Impact

How the submited vulnerability affects compliance


Web Application Security Frameworks

Applicable if the issue likely affects a web application