Deserialization in Facebook Parlai

CVE-2021-24040

Due to use of unsafe YAML deserialization logic, an attacker with the ability to modify local YAML configuration files could provide malicious input, resulting in remote code execution or similar risks. This issue affects ParlAI prior to v1.1.0.

Vulnerability class: Insecure Deserialization

EPSS: 0.174 (96.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-24040?
CVE-2021-24040 is a critical-severity vulnerability in Facebook Parlai, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2021-09-10.
How severe is CVE-2021-24040?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-24040 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.