Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over
    /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected
    servers. (CVE-2019-18835)

The remote Ubuntu 18.04 ESM host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-6076-1 advisory.

    It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were     tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to     cause a denial of service. (CVE-2019-18835, CVE-2018-12291, CVE-2018-10657)

    It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were     tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to     hijack the session. (CVE-2019-11842, CVE-2018-12423)

    It was discovered that Synapse incorrectly handled certain inputs. If a user or an automated system were     tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to     perform

    spoofing or user impersonation. (CVE-2019-5885, CVE-2018-16515)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
414005	SCA: security update for matrix-synapse (GHSA-cppw-2mf8-qpm5)	Tenable Cloud Security	SCA Checks	high
414005	SCA: security update for matrix-synapse (GHSA-cppw-2mf8-qpm5)	Tenable Self-Hosted Container Security	SCA Checks	high
175821	Ubuntu 18.04 ESM : Synapse vulnerabilities (USN-6076-1)	Nessus	Ubuntu Local Security Checks	critical

Detections

Analytics

CVE-2019-18835

high

Tenable Plugins

high

high

critical