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

> Unauthenticated remote attackers can cause service disruption in Positive Technologies MaxPatrol 8 and XSpider by exhausting session identifiers via repeated HTTPS requests.

- **Severity:** High 8.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Nov 2025
- **Updated:** 18 Nov 2025
- **Also known as:** GHSA-q46v-hq83-2jxm

## What is CVE-2021-4467?

CVE-2021-4467 is a high-severity denial of service vulnerability in Positive Technologies MaxPatrol 8 (Server), published on 14 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2021-4467?


## How do I fix CVE-2021-4467?

No fix has been published for CVE-2021-4467 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4467 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-4467 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4467 and fix it if it is affected.

What it is: CVE-2021-4467 is a high-severity denial of service vulnerability in Positive Technologies MaxPatrol 8 (Server), published on 14 Nov 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-4467 exists.

Affected product: Positive Technologies MaxPatrol 8 (Server). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-4467/ (Markdown: https://insights.sbomify.com/CVE-2021-4467/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4467
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4467
- OSV: https://osv.dev/vulnerability/CVE-2021-4467

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4467/
Summaries are generated and may contain mistakes; the official description above is the record.