Buffer overflow in Cryptography.io Cryptography

CVE-2020-36242

In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.

Vulnerability class: Integer Overflow

EPSS: 0.067 (93.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-36242?
CVE-2020-36242 is a critical-severity vulnerability in Cryptography.io Cryptography, classified under Integer Overflow or Wraparound. CVSS score: 9.1/10. Published 2021-02-07.
How severe is CVE-2020-36242?
Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2020-36242 known to be exploited?
7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.