CVE-2023-32683— URL deny list bypass via oEmbed and image URLs when generating previews in Synapse
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I. Basic Information for CVE-2023-32683
Vulnerability Information
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Vulnerability Title
URL deny list bypass via oEmbed and image URLs when generating previews in Synapse
Source: NVD (National Vulnerability Database)
Vulnerability Description
Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs) and by the limited information returned to the client: 1. For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. 2. For discovered image URLs, any non-image response is discarded. Systems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected. This issue has been addressed in version 1.85.0. Users are advised to upgrade. User unable to upgrade may also disable URL previews.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
授权机制不正确
Source: NVD (National Vulnerability Database)
Vulnerability Title
Matrix Synapse 代码问题漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Matrix Synapse是英国Matrix基金会的一款矩阵管理服务器的实现。 Matrix Synapse 1.85.0之前版本存在代码问题漏洞，该漏洞源于通过oEmbed 或URL 可以绕过 url_preview_url_blacklist 设置。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| matrix-org | synapse | < 1.85.0 | - |
II. Public POCs for CVE-2023-32683
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|---|
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- https://github.com/matrix-org/synapse/pull/15601x_refsource_MISC
- https://nvd.nist.gov/vuln/detail/CVE-2023-32683
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