CVE-2024-53863: Matrix synapse Remote Code Execution Vulnerability
HIGHCVE-2024-53863 is a HIGH remote code execution vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affecting Matrix synapse libraries in the PyPI ecosystem. The issue involves synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders. Remediation is available by upgrading affected packages to version 1.120.1.
CVE-2024-53863 at a Glance
How to Fix CVE-2024-53863
To remediate this vulnerability, upgrade all affected Matrix synapse dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
pip install matrix-synapse>=1.120.1Run the following command in your project directory to verify that all resolved dependencies use the patched release:
pip show matrix-synapseHow to Check if You Are Affected
To determine whether your Python environment is affected by CVE-2024-53863, inspect your installed packages using pip:
pip show matrix-synapseAnalyze the terminal output to locate any version of Matrix synapse in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.120.1), your application is affected.
Note: The pip show matrix-synapse command checks currently installed packages in your active Python environment.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-434: Unrestricted Upload of File with Dangerous Type, where the product allows the upload or transfer of dangerous file types that are automatically processed within its environment. In Matrix synapse, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2024-53863 Affected Matrix synapse Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
matrix-synapse
|
PyPI |
< 1.120.1
|
1.120.1
|
References
Frequently Asked Questions
What is CVE-2024-53863?
Which Matrix synapse versions are affected?
What version fixes CVE-2024-53863?
Is matrix-synapse affected?
What CWE is associated with CVE-2024-53863?
How can I check PyPI dependencies for CVE-2024-53863?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-vp6v-whfm-rv3g",
"modified" : "2024-12-03T18:44:00Z",
"published" : "2024-12-03T18:44:00Z",
"aliases" : [ "CVE-2024-53863" ],
"summary" : "Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders",
"details" : "### Impact\n\nIn Synapse versions before 1.120.1, enabling the `dynamic_thumbnails` option or processing a specially crafted request could trigger the decoding and thumbnail generation of uncommon image formats, potentially invoking external tools like Ghostscript for processing.\n\nThis significantly expands the attack surface in a historically vulnerable area, presenting a risk that far outweighs the benefit, particularly since these formats are rarely used on the open web or within the Matrix ecosystem.\n\nFor a list of image formats, as well as decoding libraries and helper programs used, see [the Pillow documentation](https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html).\n\n### Patches\n\nSynapse 1.120.1 addresses the issue by restricting thumbnail generation to images in the following widely used formats: PNG, JPEG, GIF, and WebP.\n\n### Workarounds\n\n- Ensure any image codecs and helper programs, such as Ghostscript, are patched against security vulnerabilities.\n- Uninstall unused image decoder libraries and helper programs, such as Ghostscript, from the system environment that Synapse is running in.\n - Depending on the installation method, there may be some decoder libraries bundled with Pillow and these cannot be easily uninstalled.\n - The official Docker container image does not include Ghostscript.\n\n### References\n\n- [The Pillow documentation](https://pillow.readthedocs.io/en/stable/handbook/image-file-formats.html) includes a list of supported image formats and which libraries or helper programs are used to decode them.\n\n### For more information\n\nIf you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).\n",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "PyPI",
"name" : "matrix-synapse"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "1.120.1"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/element-hq/synapse/security/advisories/GHSA-vp6v-whfm-rv3g"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-53863"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/element-hq/synapse"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-434" ],
"severity" : "HIGH",
"github_reviewed" : true,
"github_reviewed_at" : "2024-12-03T18:44:00Z",
"nvd_published_at" : "2024-12-03T17:15:12Z"
}
}