GHSA-v936-j8gp-9q3p
Vulnerability from github
6.3 (Medium) - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Impact
Requests to user provided domains were not restricted to external IP addresses when calculating the key validity for third-party invite events and sending push notifications. This could cause Synapse to make requests to internal infrastructure. The type of request was not controlled by the user, although limited modification of request bodies was possible.
For the most thorough protection server administrators should remove the deprecated federation_ip_range_blacklist
from their settings after upgrading to Synapse v1.25.0 which will result in Synapse using the improved default IP address restrictions. See the new ip_range_blacklist
and ip_range_whitelist
settings if more specific control is necessary.
Patches
Issue is resolved by #8821. Further improvements to protect homeservers by default were made in #8870 and #8954.
Workarounds
Requests to internal IP addresses could be blocked at the system or network level.
{ "affected": [ { "package": { "ecosystem": "PyPI", "name": "matrix-synapse" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "1.25.0" } ], "type": "ECOSYSTEM" } ] } ], "aliases": [ "CVE-2021-21273" ], "database_specific": { "cwe_ids": [ "CWE-601" ], "github_reviewed": true, "github_reviewed_at": "2021-02-26T17:26:48Z", "nvd_published_at": "2021-02-26T18:15:00Z", "severity": "MODERATE" }, "details": "### Impact\nRequests to user provided domains were not restricted to external IP addresses when calculating the key validity for third-party invite events and sending push notifications. This could cause Synapse to make requests to internal infrastructure. The type of request was not controlled by the user, although limited modification of request bodies was possible.\n\nFor the most thorough protection server administrators should remove the deprecated `federation_ip_range_blacklist` from their settings after upgrading to Synapse v1.25.0 which will result in Synapse using the improved default IP address restrictions. See the new `ip_range_blacklist` and `ip_range_whitelist` settings if more specific control is necessary.\n\n### Patches\nIssue is resolved by #8821. Further improvements to protect homeservers by default were made in #8870 and #8954.\n\n### Workarounds\nRequests to internal IP addresses could be blocked at the system or network level.", "id": "GHSA-v936-j8gp-9q3p", "modified": "2024-09-24T15:35:29Z", "published": "2021-02-26T17:28:34Z", "references": [ { "type": "WEB", "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3p" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21273" }, { "type": "WEB", "url": "https://github.com/matrix-org/synapse/pull/8821" }, { "type": "WEB", "url": "https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746" }, { "type": "PACKAGE", "url": "https://github.com/matrix-org/synapse" }, { "type": "WEB", "url": "https://github.com/matrix-org/synapse/releases/tag/v1.25.0" }, { "type": "WEB", "url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-131.yaml" }, { "type": "WEB", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY" } ], "schema_version": "1.4.0", "severity": [ { "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N", "type": "CVSS_V3" }, { "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N", "type": "CVSS_V4" } ], "summary": "Open redirects on some federation and push requests" }
Sightings
Author | Source | Type | Date |
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Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.