Missing Release of Resource after Effective Lifetime Affecting matrix-synapse package, versions <1.53.0-1


Severity

Recommended
0.0
medium
0
10

Snyk's Security Team recommends NVD's CVSS assessment

    Threat Intelligence

    EPSS
    0.19% (57th percentile)

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  • Snyk ID SNYK-DEBIANUNSTABLE-MATRIXSYNAPSE-3138707
  • published 23 Nov 2022
  • disclosed 22 Nov 2022

How to fix?

Upgrade Debian:unstable matrix-synapse to version 1.53.0-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream matrix-synapse package and not the matrix-synapse package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

Synapse before 1.52.0 with URL preview functionality enabled will attempt to generate URL previews for media stream URLs without properly limiting connection time. Connections will only be terminated after max_spider_size (default: 10M) bytes have been downloaded, which can in some cases lead to long-lived connections towards the streaming media server (for instance, Icecast). This can cause excessive traffic and connections toward such servers if their stream URL is, for example, posted to a large room with many Synapse instances with URL preview enabled. Version 1.52.0 implements a timeout mechanism which will terminate URL preview connections after 30 seconds. Since generating URL previews for media streams is not supported and always fails, 1.53.0 additionally implements an allow list for content types for which Synapse will even attempt to generate a URL preview. Upgrade to 1.53.0 to fully resolve the issue. As a workaround, turn off URL preview functionality by setting url_preview_enabled: false in the Synapse configuration file.

CVSS Scores

version 3.1
Expand this section

NVD

5.3 medium
  • Attack Vector (AV)
    Network
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    None
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    None
  • Integrity (I)
    None
  • Availability (A)
    Low