Vulnerability · Published Mar 11, 2021 · Assigned by facebook
CVE-2020-1900
Critical 9.8
In plain English
A critical-severity use-after-free in HHVM from Facebook. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.4% (higher than 72% of all known vulnerabilities).
Severity (CVSS NVD)9.8Critical
Exploit odds (30 days)1.4%top 27.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official 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 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.
Affected products (as reported)
Weakness: CWE-416
References
- https://hhvm.com/blog/2020/06/30/security-update.html x_refsource_CONFIRM
- https://github.com/facebook/hhvm/commit/c1c4bb0cf9e076aafaf4ff3515556ef9faf906f3 x_refsource_MISC