CVE-2021-21393
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2021-21393
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21393.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2021-21393
- Aliases
- Related
- Published
- 2021-04-12T22:15:13Z
- Modified
- 2025-05-10T23:56:14.452571Z
- Severity
-
- 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 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 1.28.0 Synapse is missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. Note that the groups feature is not part of the Matrix specification and the chosen maximum lengths are arbitrary. Not all clients might abide by them. Refer to referenced GitHub security advisory for additional details including workarounds.
- References
-
- https://github.com/matrix-org/synapse/security/advisories/GHSA-jrh7-mhhx-6h88
- https://github.com/matrix-org/synapse/pull/9321
- https://github.com/matrix-org/synapse/pull/9393
- https://pypi.org/project/matrix-synapse/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
Affected packages
Git / github.com/matrix-org/synapse
Affected ranges
- Type
- GIT
- Repo
- https://github.com/matrix-org/synapse
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixed
Affected versions
0.*
0.34.0rc2
1.*
1.7.2
Other
alpha
hhs-1
hhs-2
hhs-3
hhs-4
hhs-5
hhs-6
hhs-7
hhs-8
v0.*
v0.0.0
v0.0.1
v0.1.0
v0.1.1
v0.1.2
v0.10.0
v0.10.0-r1
v0.10.0-r2
v0.10.0-rc1
v0.10.0-rc2
v0.10.0-rc3
v0.10.0-rc4
v0.10.0-rc5
v0.10.0-rc6
v0.10.1-rc1
v0.11.0
v0.11.0-r1
v0.11.0-r2
v0.11.0-rc1
v0.11.0-rc2
v0.11.1
v0.12.0
v0.12.0-rc1
v0.12.0-rc2
v0.12.0-rc3
v0.12.1-rc1
v0.13.0
v0.13.1
v0.13.2
v0.13.3
v0.14.0
v0.14.0-rc1
v0.14.0-rc2
v0.15.0-rc1
v0.16.0
v0.16.0-rc1
v0.16.0-rc2
v0.16.1
v0.16.1-r1
v0.16.1-rc1
v0.17.0
v0.17.0-rc1
v0.17.0-rc2
v0.17.0-rc3
v0.17.0-rc4
v0.17.1
v0.17.1-rc1
v0.17.2
v0.17.2-rc1
v0.17.3
v0.18.0
v0.18.0-rc1
v0.18.1
v0.18.1-rc1
v0.18.2
v0.18.2-rc1
v0.18.2-rc2
v0.18.2-rc3
v0.18.2-rc4
v0.18.2-rc5
v0.18.3
v0.18.4
v0.18.4-rc1
v0.18.5
v0.18.5-rc1
v0.18.5-rc2
v0.18.5-rc3
v0.18.6
v0.18.6-rc1
v0.18.6-rc2
v0.18.6-rc3
v0.18.7
v0.18.7-rc1
v0.18.7-rc2
v0.19.0
v0.19.0-rc1
v0.19.0-rc2
v0.19.0-rc3
v0.19.0-rc4
v0.19.1
v0.19.2
v0.19.3
v0.19.3-rc1
v0.19.3-rc2
v0.2.0
v0.2.1
v0.2.1a
v0.2.2
v0.2.3
v0.20.0
v0.20.0-rc1
v0.21.0
v0.21.0-rc1
v0.21.0-rc2
v0.21.0-rc3
v0.21.1
v0.22.0
v0.22.0-rc1
v0.22.0-rc2
v0.22.1
v0.23.0
v0.23.0-rc1
v0.23.0-rc2
v0.23.1
v0.24.0
v0.24.0-rc1
v0.24.1
v0.25.0
v0.25.0-rc1
v0.25.1
v0.26.0
v0.26.0-rc1
v0.26.1
v0.27.0
v0.27.0-rc1
v0.27.0-rc2
v0.27.1
v0.27.2
v0.27.3
v0.27.3-rc1
v0.27.3-rc2
v0.27.4
v0.28.0
v0.28.0-rc1
v0.28.1
v0.29.0
v0.29.0-rc1
v0.29.1
v0.3.0
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.30.0
v0.30.0-rc1
v0.31.0
v0.31.0-rc1
v0.31.1
v0.31.2
v0.32.0
v0.32.0rc1
v0.32.1
v0.32.2
v0.33.0
v0.33.0rc1
v0.33.1
v0.33.2
v0.33.2rc1
v0.33.3
v0.33.3.1
v0.33.3rc1
v0.33.3rc2
v0.33.4
v0.33.4rc1
v0.33.4rc2
v0.33.5
v0.33.5.1
v0.33.5rc1
v0.33.6
v0.33.6rc1
v0.33.7
v0.33.7rc1
v0.33.7rc2
v0.33.8
v0.33.8rc1
v0.33.8rc2
v0.33.9
v0.33.9rc1
v0.34.0
v0.34.0rc1
v0.34.0rc2
v0.34.1
v0.34.1+1
v0.34.1.1
v0.34.1rc1
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
v0.9.3-rc1
v0.99.0
v0.99.0rc1
v0.99.0rc2
v0.99.0rc3
v0.99.0rc4
v0.99.1
v0.99.1.1
v0.99.1rc1
v0.99.1rc2
v0.99.2
v0.99.2rc1
v0.99.3
v0.99.3.1
v0.99.3.2
v0.99.3rc1
v0.99.4
v0.99.4rc1
v0.99.5
v0.99.5.1
v0.99.5.1.dev0
v0.99.5.2
v0.99.5rc1
v1.*
v1.0.0
v1.0.0rc1
v1.0.0rc2
v1.0.0rc3
v1.1.0
v1.1.0rc1
v1.1.0rc2
v1.10.0
v1.10.0rc1
v1.10.0rc2
v1.10.0rc3
v1.10.0rc5
v1.10.1
v1.11.0
v1.11.0rc1
v1.11.1
v1.12.0
v1.12.0rc1
v1.12.1
v1.12.1rc1
v1.12.2
v1.12.3
v1.12.4
v1.12.4rc1
v1.13.0
v1.13.0rc1
v1.13.0rc2
v1.13.0rc3
v1.14.0
v1.14.0rc1
v1.14.0rc2
v1.15.0
v1.15.0rc1
v1.15.1
v1.15.2
v1.16.0
v1.16.0rc1
v1.16.0rc2
v1.16.1
v1.17.0
v1.17.0rc1
v1.18.0
v1.18.0rc1
v1.18.0rc2
v1.19.0
v1.19.0rc1
v1.19.1
v1.19.1rc1
v1.19.2
v1.19.3
v1.2.0
v1.2.0rc1
v1.2.0rc2
v1.2.1
v1.20.0
v1.20.0rc1
v1.20.0rc2
v1.20.0rc3
v1.20.0rc4
v1.20.0rc5
v1.20.1
v1.21.0
v1.21.0rc1
v1.21.0rc2
v1.21.0rc3
v1.21.1
v1.21.2
v1.22.0
v1.22.0rc1
v1.22.0rc2
v1.22.1
v1.23.0
v1.23.0rc1
v1.23.1
v1.24.0
v1.24.0rc1
v1.24.0rc2
v1.25.0
v1.25.0rc1
v1.26.0
v1.26.0-deb
v1.26.0rc1
v1.26.0rc2
v1.27.0
v1.27.0rc1
v1.27.0rc2
v1.28.0rc1
v1.3.0
v1.3.0rc1
v1.3.1
v1.4.0
v1.4.0rc1
v1.4.0rc2
v1.4.1
v1.4.1rc1
v1.5.0
v1.5.0rc1
v1.5.0rc2
v1.5.1
v1.6.0
v1.6.0rc1
v1.6.0rc2
v1.6.1
v1.7.0
v1.7.0rc1
v1.7.0rc2
v1.7.1
v1.7.2
v1.7.3
v1.8.0
v1.8.0rc1
v1.9.0
v1.9.0.dev1
v1.9.0.dev2
v1.9.0rc1
v1.9.1