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 appearing to have come from another person. Such messages will be marked with a grey shield on some platforms, but this may be missing in others. This attack is possible due to the matrix-ios-sdk implementing a too permissive key forwarding strategy. The default policy for accepting key forwards has been made more strict in the matrix-ios-sdk version 0.23.19. matrix-ios-sdk will now only accept forwarded keys in response to previously issued requests and only from own, verified devices. The SDK now sets a `trusted` flag on the decrypted message upon decryption, based on whether the key used to decrypt the message was received from a trusted source. Clients need to ensure that messages decrypted with a key with `trusted = false` are decorated appropriately (for example, by showing a warning for such messages). This attack requires coordination between a malicious home server and an attacker, so those who trust their home servers do not need a workaround.

Orckestra C1 CMS is a .NET based Web Content Management System. A vulnerability in versions prior to 6.13 allows remote attackers to execute arbitrary code on affected installations of Orckestra C1 CMS. Authentication is required to exploit this vulnerability. The authenticated user may perform the actions unknowingly by visiting a specially crafted site. This issue is patched in C1 CMS v6.13. There are no known workarounds.

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.

matrix-nio is a Python Matrix client library, designed according to sans I/O principles. Prior to version 0.20, when a users requests a room key from their devices, the software correctly remember the request. Once they receive a forwarded room key, they accept it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.20 fixes the issue.

Git is an open source, scalable, distributed revision control system. Versions prior to 2.30.6, 2.31.5, 2.32.4, 2.33.5, 2.34.5, 2.35.5, 2.36.3, and 2.37.4 are subject to exposure of sensitive information to a malicious actor. When performing a local clone (where the source and target of the clone are on the same volume), Git copies the contents of the source’s `$GIT_DIR/objects` directory into the destination by either creating hardlinks to the source contents, or copying them (if hardlinks are disabled via `–no-hardlinks`). A malicious actor could convince a victim to clone a repository with a symbolic link pointing at sensitive information on the victim’s machine. This can be done either by having the victim clone a malicious repository on the same machine, or having them clone a malicious repository embedded as a bare repository via a submodule from any source, provided they clone with the `–recurse-submodules` option. Git does not create symbolic links in the `$GIT_DIR/objects` directory. The problem has been patched in the versions published on 2022-10-18, and backported to v2.30.x. Potential workarounds: Avoid cloning untrusted repositories using the `–local` optimization when on a shared machine, either by passing the `–no-local` option to `git clone` or cloning from a URL that uses the `file://` scheme. Alternatively, avoid cloning repositories from untrusted sources with `–recurse-submodules` or run `git config –global protocol.file.allow user`.

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust, and matrix-sdk-crypto is the Matrix encryption library. Prior to version 0.6, when a user requests a room key from their devices, the software correctly remembers the request. When the user receives a forwarded room key, the software accepts it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.6 fixes this issue.