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OpenAdvisories
High USN-6076-1 7 CVEs

matrix-synapse vulnerabilities

Published May 16, 2023 · Updated Feb 10, 2026

Ecosystem: Ubuntu

Summary

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)

Fixed packages 1

ReleasePackageFixed in
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS matrix-synapse 0.24.0+dfsg-1ubuntu0.1~esm1

Vulnerabilities 7

  • High 8.8
    CVE-2018-16515

    Matrix Synapse Improper Signature Validation

    Matrix Synapse before 0.33.3.1 allows remote attackers to spoof events and possibly have unspecified other impacts by leveraging improper transaction and event signature validation.

    matrix-synapse matrix-synapse Ubuntu PyPI
  • High 8.6
    CVE-2019-18835

    Improper Verification of Cryptographic Signature in matrix-synapse

    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.

    matrix-synapse matrix-synapse Ubuntu PyPI
  • High 7.5
    CVE-2018-10657

    Matrix Synapse DoS

    Matrix Synapse before 0.28.1 is prone to a denial of service flaw where malicious events injected with depth = 2^63 - 1 render rooms unusable, related to federation/federation_base.py and handlers/message.py, as exploited in the wild in April 2018.

    matrix-synapse matrix-synapse Ubuntu PyPI
  • High 7.5
    CVE-2018-12291

    Matrix Synapse Security Filtering Flaw

    The on_get_missing_events function in handlers/federation.py in Matrix Synapse before 0.31.1 has a security bug in the get_missing_events federation API where event visibility rules were not applied correctly.

    matrix-synapse matrix-synapse Ubuntu PyPI
  • High 7.5
    CVE-2018-12423

    Matrix Synapse Authorization Error

    In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.

    matrix-synapse matrix-synapse Ubuntu PyPI
  • High 7.5
    CVE-2019-11842

    matrix-sydent and matrix-synapse Use Cryptographically Weak PRNG

    An issue was discovered in Matrix Sydent before 1.0.3 and Synapse before 0.99.3.1. Random number generation is mishandled, which makes it easier for attackers to predict a Sydent authentication token or a Synapse random ID.

    matrix-synapse matrix-synapse matrix-sydent Ubuntu PyPI
  • High 7.5
    CVE-2019-5885

    Matrix Synapse Predictable Secret Key

    Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other secrets which could allow remote attackers to impersonate users.

    matrix-synapse matrix-synapse Ubuntu PyPI

References

  • report
    https://ubuntu.com/security/CVE-2018-10657
  • report
    https://ubuntu.com/security/CVE-2018-12291
  • report
    https://ubuntu.com/security/CVE-2018-12423
  • report
    https://ubuntu.com/security/CVE-2018-16515
  • report
    https://ubuntu.com/security/CVE-2019-5885
  • report
    https://ubuntu.com/security/CVE-2019-11842
  • report
    https://ubuntu.com/security/CVE-2019-18835