CVE-2022-39255
Matrix iOS SDK allows developers to build iOS apps compatible with Matrix.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Matrix iOS SDK allows developers to build iOS apps compatible with Matrix. Prior to version 0.23.19, an attacker cooperating with a malicious homeserver can construct messages that legitimately appear to have come from another person, without any indication such as a grey shield. Additionally, a sophisticated attacker cooperating with a malicious homeserver could employ this vulnerability to perform a targeted attack in order to send fake to-device messages appearing to originate from another user. This can allow, for example, to inject the key backup secret during a self-verification, to make a targeted device start using a malicious key backup spoofed by the homeserver. These attacks are possible due to a protocol confusion vulnerability that accepts to-device messages encrypted with Megolm instead of Olm. matrix-ios-sdk version 0.23.19 has been modified to only accept Olm-encrypted to-device messages. Out of caution, several other checks have been audited or added. This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround. To avoid malicious backup attacks, one should not verify one's new logins using emoji/QR verifications methods until patched.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.83% probability · 55th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287, CWE-322
- Affected
- matrix/software development kit
- Source
- security-advisories@github.com
References
- https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262cPatch, Third Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19Release Notes, Third Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-hw6g-j8v6-9hcmThird Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clientsVendor Advisory
- https://github.com/matrix-org/matrix-ios-sdk/commit/5ca86c328a5faaab429c240551cb9ca8f0f6262cPatch, Third Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/releases/tag/v0.23.19Release Notes, Third Party Advisory
- https://github.com/matrix-org/matrix-ios-sdk/security/advisories/GHSA-hw6g-j8v6-9hcmThird Party Advisory
- https://matrix.org/blog/2022/09/28/upgrade-now-to-address-encryption-vulns-in-matrix-sdks-and-clientsVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.