GHSA-98PX-6486-J7QC
Vulnerability from github – Published: 2023-06-06 16:41 – Updated: 2024-09-30 20:34Impact
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:
- For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded.
- 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.
Because of the uncommon configuration required, the limited information a malicious user, and the amount of guesses/time the attack would need; the severity is rated as low.
Patches
The issue is fixed by #15601.
Workarounds
The default configuration of the url_preview_ip_range_blacklist should protect against requests being made to internal infrastructure, URL previews of public URLs is expected.
Alternately URL previews could be disabled using the url_preview_enabled setting.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "matrix-synapse"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.85.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2023-32683"
],
"database_specific": {
"cwe_ids": [
"CWE-863",
"CWE-918"
],
"github_reviewed": true,
"github_reviewed_at": "2023-06-06T16:41:34Z",
"nvd_published_at": "2023-06-06T19:15:11Z",
"severity": "MODERATE"
},
"details": "### Impact\nA 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:\n\n* For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded.\n* For discovered image URLs, any non-image response is discarded.\n\nSystems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected.\n\nBecause of the uncommon configuration required, the limited information a malicious user, and the amount of guesses/time the attack would need; the severity is rated as low.\n\n### Patches\n\nThe issue is fixed by #15601.\n\n### Workarounds\n\nThe default configuration of the `url_preview_ip_range_blacklist` should protect against requests being made to internal infrastructure, URL previews of public URLs is expected.\n\nAlternately URL previews could be disabled using the `url_preview_enabled` setting.",
"id": "GHSA-98px-6486-j7qc",
"modified": "2024-09-30T20:34:41Z",
"published": "2023-06-06T16:41:34Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-32683"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/pull/15601"
},
{
"type": "PACKAGE",
"url": "https://github.com/matrix-org/synapse"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/synapse/releases/tag/v1.85.0"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-85.yaml"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/X6DH5A5YEB5LRIPP32OUW25FCGZFCZU2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Synapse has URL deny list bypass via oEmbed and image URLs when generating previews"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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