Vulnerability · Published May 7, 2021 · Assigned by GitHub_M

CVE-2021-21419Improper Handling of Highly Compressed Data (Data Amplification) and Memory Allocation with Excessive Size Value in eventlet

Medium 5.3

In plain English

A medium-severity uncontrolled resource consumption in eventlet from eventlet. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.8% (higher than 78% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)1.8%top 21.5% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

Official description

Eventlet is a concurrent networking library for Python. A websocket peer may exhaust memory on Eventlet side by sending very large websocket frames. Malicious peer may exhaust memory on Eventlet side by sending highly compressed data frame. A patch in version 0.31.0 restricts websocket frame to reasonable limits. As a workaround, restricting memory usage via OS limits would help against overall machine exhaustion, but there is no workaround to protect Eventlet process.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	python-eventlet	0.26.1-7	DEBIAN-CVE-2021-21419
Debian:13	python-eventlet	0.26.1-7	DEBIAN-CVE-2021-21419
Debian:14	python-eventlet	0.26.1-7	DEBIAN-CVE-2021-21419
PyPI	eventlet	0.31.0	GHSA-9p9m-jm8w-94p2
PyPI	eventlet	0.31.0	PYSEC-2021-12

Affected products (as reported)

Vendor	Product	Versions
eventlet	eventlet	>= 0.10, < 0.31.0

Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/eventlet/eventlet/security/advisories/GHSA-9p9m-jm8w-94p2 x_refsource_CONFIRM
FEDORA-2021-9fde3d7ab1 vendor-advisory, x_refsource_FEDORA
FEDORA-2021-d5915c247b vendor-advisory, x_refsource_FEDORA