CVE-2022-36009

Dashboard / Vulnerabilities / CVE-2022-36009

CVE-2022-36009

Summary: Incorrect parsing of access level in gomatrixserverlib and dendrite

Details: gomatrixserverlib is a Go library for matrix protocol federation. Dendrite is a Matrix homeserver written in Go, an alternative to Synapse. The power level parsing within gomatrixserverlib was failing to parse the `"events_default"` key of the `m.room.power_levels` event, defaulting the event default power level to zero in all cases. Power levels are the matrix terminology for user access level. In rooms where the `"events_default"` power level had been changed, this could result in events either being incorrectly authorised or rejected by Dendrite servers. gomatrixserverlib contains a fix as of commit `723fd49` and Dendrite 0.9.3 has been updated accordingly. Matrix rooms where the `"events_default"` power level has not been changed from the default of zero are not vulnerable. Users are advised to upgrade. There are no known workarounds for this issue.

References: https://matrix.org/docs/guides/moderation/#power-levels, https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/36xxx/CVE-2022-36009.json, https://github.com/matrix-org/gomatrixserverlib/security/advisories/GHSA-grvv-h2f9-7v9c, https://nvd.nist.gov/vuln/detail/CVE-2022-36009, https://github.com/matrix-org/gomatrixserverlib/commit/723fd495dde835d078b9f2074b6b62c06dea4575