CVE-2020-1899: facebook hhvm Untrusted Pointer Dereference

Vulnerability summary

CVE-2020-1899 is a high (CVSS 7.5) Untrusted Pointer Dereference vulnerability in facebook hhvm. EPSS estimates a 1.22% chance of exploitation in the next 30 days, higher than 68.2% of scored vulnerabilities.

Timeline

1. 11-03-2021
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

Description

The unserialize() function supported a type code, "S", which was meant to be supported only for APC serialization. This type code allowed arbitrary memory addresses to be accessed as if they were static StringData objects. This issue affected HHVM prior to v4.32.3, between versions 4.33.0 and 4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.

• CWE-822Untrusted Pointer DereferenceThe product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer.
• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.