CVE-2021-4467

Positive Technologies MaxPatrol 8 & XSpider Remote DoS

Positive Technologies MaxPatrol 8 and XSpider contain a remote denial-of-service vulnerability in the client communication service on TCP port 2002. The service generates a new session identifier for each incoming connection without adequately limiting concurrent requests. An unauthenticated remote attacker can repeatedly issue HTTPS requests to the service, causing excessive allocation of session identifiers. Under load, session identifier collisions may occur, forcing active client sessions to disconnect and resulting in service disruption.

Affected

Positive Technologies · MaxPatrol 8 (Server) · XSpider (Server)

CVSS v4.0 VULNCHECK

8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS

0.49% chance of exploitation in the next 30 days, 41st percentile

Published

2025-11-14

Updated

2025-11-18

Proof-of-concept exploits (2)

• https://vulners.com/zdt/1337DAY-ID-36775
• https://cxsecurity.com/issue/WLB-2021090114

References

• CVE Record
• NVD entry