CVE-2020-1900

Name of the Vulnerable Software and Affected Versions: HHVM versions prior to 4.32.3 HHVM versions 4.33.0 through 4.62.0

Description: When unserializing an object with dynamic properties, HHVM needs to pre-reserve the full size of the dynamic property array before inserting anything into it. Otherwise, the array might resize, invalidating previously stored references. This pre-reservation was not occurring in HHVM for the specified versions.

Recommendations: For HHVM versions prior to 4.32.3, update to version 4.32.3 or later. For HHVM versions 4.33.0 through 4.62.0, update to a version later than 4.62.0. At the moment, there is no information about a newer version that contains a fix for this vulnerability.