CVE-2022-39255 Matrix iOS SDK vulnerable ton Olm/Megolm protocol confusion
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2022-39255?
CVE-2022-39255 is a high-severity vulnerability in matrix-org matrix-ios-sdk, published on 28 Sep 2022.
Official 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.
Which versions are affected by CVE-2022-39255?
It affects 1 product.
Products include Matrix Software Development Kit.
How do I fix CVE-2022-39255?
No fix has been published for CVE-2022-39255 yet. Limit exposure of the affected software until one is available.
Is CVE-2022-39255 being exploited?
There is no known exploitation of CVE-2022-39255 in the wild and no public exploit code.
Other vulnerabilities in matrix-org matrix-ios-sdk
Sources
Also known as GHSA-hw6g-j8v6-9hcm.