CVE-2020-36242
python-cryptography: Large inputs for symmetric encryption can trigger integer overflow leading to buffer overflow
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 9, 2020
Updated · June 28, 2026
Description
A buffer-overflow flaw was found in the python-cryptography package. In certain sequences of update() calls when symmetrically encrypting very large payloads (>2GB) could result in an integer overflow, leading to buffer overflows. Note: This fix is a workaround for the OpenSSL CVE-2021-23840 flaw. Source: pyca/cryptography project
Statement
Triggering this flaw on in versions of python-cryptography as shipped with Red Hat Enterprise Linux 8 BaseOS, Appstream, as well as Red Hat Software Collections, can result in denial of service due to memory consumption or MemoryError exception.
In Red Hat OpenStack Platform, because the flaw has a lower impact and the fix would require a substantial amount of development, no update will be provided at this time for the RHOSP python-cryptography package.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
CWE-190 · Integer Overflow or Wraparound