Integer overflow in Ruby-lang Cgi

CVE-2021-41816

CGI.escape_html in Ruby before 2.7.5 and 3.x before 3.0.3 has an integer overflow and resultant buffer overflow via a long string on platforms (such as Windows) where size_t and long have different numbers of bytes. This also affects the C…

Vulnerability class: Integer Overflow

EPSS: 0.048 (90.9th 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-2021-41816?
CVE-2021-41816 is a critical-severity vulnerability in Ruby-lang Cgi, classified under Integer Overflow or Wraparound. CVSS score: 9.8/10. Published 2022-02-06.
How severe is CVE-2021-41816?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-41816 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.