CVE-2021-30481

HIGH

Steam Client < 2021-04-10 - Authenticated Remote Code Execution via Steam Invite Buffer Overflow

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2021-30481. PoCs published by floesen.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2021-30481, a remote code execution vulnerability in Counter-Strike: Global Offensive (CS:GO) via malicious screenshot responses. The exploit leverages ROP chains and shellcode to achieve arbitrary code execution on the victim's machine.

Description

Valve Steam before 2021-04-17, when a Source engine game is installed, allows remote authenticated users to execute arbitrary code because of a buffer overflow that occurs for a Steam invite after one click.

Exploits (1)

nomisec WORKING POC 58 stars
by floesen · poc
https://github.com/floesen/CVE-2021-30481

This repository contains a functional exploit for CVE-2021-30481, a remote code execution vulnerability in Counter-Strike: Global Offensive (CS:GO) via malicious screenshot responses. The exploit leverages ROP chains and shellcode to achieve arbitrary code execution on the victim's machine.

Classification
Working Poc 95%
Attack Type
Rce
Complexity
Complex
Reliability
Reliable
Target: Counter-Strike: Global Offensive (CS:GO)
Auth required
Prerequisites: Victim's SteamID · SteamworksPy library · Network connectivity to victim
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (4)

Core 4
Core References
Issue Tracking, Third Party Advisory
https://news.ycombinator.com/item?id=26762170
Exploit, Third Party Advisory
https://www.youtube.com/watch?v=rNQn--9xR1Q

Scores

CVSS v3 8.0
EPSS 0.0350
EPSS Percentile 87.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H

Details

CWE
CWE-120
Status published
Products (1)
valvesoftware/steam_client < 2021-04-10
Published Apr 10, 2021
Tracked Since Feb 18, 2026