MobilityDB version 1.3.0 and earlier contains an out-of-bounds read vulnerability in the MEOS binary and library WKB deserialization logic that allows unprivileged database users to crash the PostgreSQL backend process by supplying a crafted WKB payload with a negative length field. The negative length value wraps to a large unsigned size_t due to missing signed validation, bypasses an overflow-unsafe pointer arithmetic bounds check in wkb_parse_state_check(), and causes memcpy() in text_from_wkb_state() to operate with a corrupted unbounded length, resulting in a remote denial-of-service condition affecting all sessions on the PostgreSQL instance.
Weakness
The product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.
Extended Description
It is dangerous to rely on implicit casts between signed and unsigned numbers because the result can take on an unexpected value and violate assumptions made by the program. Often, functions will return negative values to indicate a failure. When the result of a function is to be used as a size parameter, using these negative return values can have unexpected results. For example, if negative size values are passed to the standard memory copy or allocation functions they will be implicitly cast to a large unsigned value. This may lead to an exploitable buffer overflow or underflow condition.
References
- https://github.com/MobilityDB/MobilityDB/releases/tag/v1.2.2
- https://github.com/MobilityDB/MobilityDB/releases/tag/v1.3.1
- https://github.com/MobilityDB/MobilityDB/security/advisories/GHSA-2c92-2w7c-pm3g
- https://www.vulncheck.com/advisories/mobilitydb-through-out-of-bounds-read-dos-via-wkb-deserialization