AUGUST 4, 2026
Live Feed
Back to database
Case File

CVE-2021-3177

CRITICAL · CVSS 9.8 EPSS 23.29% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-01-19 · Last synced 2026-08-04

CyberRota Analysis

This is a critical severity vulnerability with a CVSS score of 9.8. Public exploit code or proof-of-concept references have been detected in its references. Its EPSS score suggests a 23.3% probability of exploitation in the next 30 days. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-3177
Severity
CRITICAL
CVSS
9.8
EPSS
23.29%

Original NVD Description

Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Python applications that accept floating-point numbers as untrusted input, as demonstrated by a 1e300 argument to c_double.from_param. This occurs because sprintf is used unsafely.

Related CVEs

Other vulnerabilities affecting the same vendor(s)