Impact Passing untrusted input as part of a database or collection name may result in targeting a different database or collection than specified.

Patches Fixed in PHP library 1.21.4 and 2.4.1.

Workarounds Validate database and collection names prior to passing into APIs.

An out-of-bounds read in the BSON decoding component of the MongoDB PHP driver may allow an unauthenticated party who supplies specially formed input to have a small amount of adjacent process memory copied into an error message that is returned to application code. This may result in unintended disclosure of limited memory contents.

The BSON encoder in the MongoDB PHP Driver does not check some return values after a document exceeds libbson's size limit. This can leave the encoder in an invalid state. An unauthenticated actor who can cause an affected application to encode an unusually large data structure can terminate the PHP worker or cause the resulting document to omit fields. No MongoDB server connection or database authentication is required.

The BSON encoder in the MongoDB PHP Driver converts a string length to a 32-bit value without validation. When an affected application encodes a string near 4 GiB, the allocation size can wrap while the copy operation uses the original length. The resulting heap buffer overflow can corrupt process memory or terminate the PHP process. Reaching this issue requires a non-default runtime configuration that permits multi-gigabyte values. No MongoDB server interaction is required.