CVE-2021-29471

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Source
https://cve.org/CVERecord?id=CVE-2021-29471
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-29471.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2021-29471
Aliases
Downstream
Related
Published
2021-05-11T15:15:08Z
Modified
2026-10-16T02:50:01Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
[none]
Details

Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 "Push rules" can specify conditions under which they will match, including event_match, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.

Database specific 
{
    "unresolved_ranges":  [
        {
            "cpes":  [
                "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "extracted_events":  [
                {
                    "range":  [
                        {
                            "introduced":  "34"
                        },
                        {
                            "last_affected":  "34"
                        }
                    ],
                    "source":  "CPE_STRING"
                }
            ],
            "vendor_product":  "fedoraproject:fedora"
        }
    ]
}
References

Affected packages

Git / github.com/matrix-org/synapse

Affected ranges

Type
GIT
Repo
https://github.com/matrix-org/synapse
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
d1473f7362e9b146dbd256076c8e3c7d163e7d94
Fixed
03318a766cac9f8b053db2214d9c332a977d226c
Database specific
Show details 
{
    "extracted_events":  [
        {
            "cpe":  "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*",
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "1.33.2"
                }
            ],
            "source":  "CPE_RANGE"
        },
        {
            "range":  [
                {
                    "fixed":  "03318a766cac9f8b053db2214d9c332a977d226c"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v1.33.2",
            "range":  [
                {
                    "fixed":  "d1473f7362e9b146dbd256076c8e3c7d163e7d94"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

Other
hhs-1
hhs-2
hhs-3
hhs-5
hhs-6
hhs-7
hhs-8
v0.*
v0.10.0
v0.10.0-r1
v0.10.0-r2
v0.11.0
v0.11.0-r1
v0.11.0-r2
v0.11.1
v0.12.0
v0.13.1
v0.13.2
v0.13.3
v0.14.0
v0.16.0
v0.16.1
v0.16.1-r1
v0.17.0
v0.17.1
v0.17.2
v0.17.3
v0.18.0
v0.18.1
v0.18.2
v0.18.3
v0.18.4
v0.18.5
v0.2.0
v0.2.1
v0.2.1a
v0.2.2
v0.23.0-rc1
v0.23.0-rc2
v0.25.0-rc1
v0.28.0-rc1
v0.3.0
v0.3.3
v0.3.4
v0.32.0
v0.32.0rc1
v0.32.2
v0.4.1
v0.4.2
v0.5.0
v0.5.1
v0.5.2
v0.5.3
v0.5.3a
v0.5.3b
v0.5.3c
v0.5.4
v0.5.4a
v0.6.0
v0.6.0a
v0.6.0b
v0.6.1
v0.6.1a
v0.6.1b
v0.6.1c
v0.6.1d
v0.6.1e
v0.6.1f
v0.7.0
v0.7.0a
v0.7.0b
v0.7.0c
v0.7.0d
v0.7.0e
v0.7.0f
v0.7.1
v0.7.1-r1
v0.7.1-r2
v0.7.1-r3
v0.7.1-r4
v0.8.0
v0.8.1
v0.8.1-r1
v0.8.1-r2
v0.8.1-r3
v0.8.1-r4
v0.9.0
v0.9.0-r1
v0.9.0-r2
v0.9.0-r3
v0.9.0-r4
v0.9.0-r5
v0.9.1
v0.9.2
v0.9.2-r1
v0.9.2-r2
v0.9.3
v0.99.1rc1
v0.99.2rc1
v0.99.4rc1
v0.99.5.1.dev0
v1.*
v1.1.0rc1
v1.1.0rc2
v1.10.0rc1
v1.11.0rc1
v1.12.0rc1
v1.14.0rc1
v1.15.0rc1
v1.16.0rc1
v1.17.0rc1
v1.18.0rc1
v1.23.0rc1
v1.24.0rc1
v1.27.0rc1
v1.29.0rc1
v1.3.0rc1
v1.30.0rc1
v1.31.0rc1
v1.32.0rc1
v1.33.0
v1.33.0rc1
v1.33.0rc2
v1.33.1
v1.4.0rc1
v1.5.0rc1
v1.6.0rc1
v1.8.0rc1
v1.9.0.dev1
v1.9.0.dev2
v1.9.0rc1

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2021-29471.json"