CVE-2021-44362 – This vulnerability allows remote attackers to c... (How to Fix)

Q: What is the severity of CVE-2021-44362?

CVE-2021-44362 has a CVSS score of 7.7 (HIGH). This vulnerability allows remote attackers to cause a denial of service by sending a specially crafted HTTP request to the Reolink RLC-410W camera's cgiserver.cgi JSON parser. The malformed SetCloudSchedule parameter triggers a device reboot. This affects users of Reolink RLC-410W cameras running vulnerable firmware.

📋 TL;DR

This vulnerability allows remote attackers to cause a denial of service by sending a specially crafted HTTP request to the Reolink RLC-410W camera's cgiserver.cgi JSON parser. The malformed SetCloudSchedule parameter triggers a device reboot. This affects users of Reolink RLC-410W cameras running vulnerable firmware.

💻 Affected Systems

Products:

Reolink RLC-410W

Versions: v3.0.0.136_20121102

Operating Systems: Embedded firmware

Default Config Vulnerable: ⚠️ Yes

Notes: Affects the specific firmware version mentioned; other versions may also be vulnerable but not confirmed.

📦 What is this software?

Rlc 410w Firmware by Reolink

View all CVEs affecting Rlc 410w Firmware →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Persistent device unavailability through repeated exploitation, disrupting surveillance coverage and potentially enabling physical security breaches during downtime.

🟠

Likely Case

Temporary camera reboot causing surveillance gaps, requiring manual intervention to restore functionality.

🟢

If Mitigated

Minimal impact with proper network segmentation and access controls preventing external exploitation attempts.

🌐 Internet-Facing: HIGH - Directly exploitable via HTTP requests without authentication, making internet-exposed devices prime targets.

🏢 Internal Only: MEDIUM - Internal attackers or compromised internal systems could exploit this, but requires network access to the camera.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires sending a malformed HTTP request with a non-object SetCloudSchedule parameter to the cgiserver.cgi endpoint.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check Reolink for updated firmware

Vendor Advisory: https://reolink.com/support/security-advisories/

Restart Required: Yes

Instructions:

1. Check current firmware version via camera web interface. 2. Download latest firmware from Reolink support site. 3. Upload firmware via web interface. 4. Reboot camera after update completes.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate cameras on separate VLAN without internet access

Access Control Lists

all

Restrict HTTP access to camera management interface to trusted IPs only

🧯 If You Can't Patch

Implement strict network segmentation to isolate cameras from untrusted networks
Deploy web application firewall rules to block malformed JSON requests to cgiserver.cgi

🔍 How to Verify

Check if Vulnerable:

Check firmware version in camera web interface under Settings > System > Firmware

Check Version:

curl -s http://camera-ip/cgi-bin/cgiserver.cgi?cmd=getSystemInfo | grep version

Verify Fix Applied:

Verify firmware version matches or exceeds patched version after update

📡 Detection & Monitoring

Log Indicators:

Unexpected device reboots
HTTP requests to cgiserver.cgi with malformed JSON

Network Indicators:

HTTP POST requests to /cgi-bin/cgiserver.cgi with SetCloudSchedule parameter

SIEM Query:

source="camera-logs" AND (event="reboot" OR uri="/cgi-bin/cgiserver.cgi")

📊 Metadata

CVE ID: CVE-2021-44362

CVSS v3 Score: 7.7 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CWE: CWE-20

Published: January 28, 2022

Last Updated: November 21, 2024

🔗 References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1421 Exploit,Technical Description,Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1421 Exploit,Technical Description,Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

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