CVE•Published 2022-03-04•Modified 2026-10-14•1 article on news•5 live references•NVD data

CVE-2021-3737Python · Python

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

Exploit Prediction Scoring System · top 4% of all CVEs

Weaknesses (CWE)

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')CWE-400Uncontrolled Resource Consumption

Description

A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop, consuming CPU time. The highest threat from this vulnerability is to system availability.

Timeline

Published 2022-03-04

Modified 2026-10-14

External references

NVD MITRE Exploit-DB trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag38,613 hosts

vuln:CVE-2021-3737

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Python Python"

All exposed Python Python instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Python"

HTTP body or banner mentions "Python" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2021-3737