CVE-2021-36999 – A buffer overflow vulnerability in Huawei smart... (How to Fix)

Q: What is the severity of CVE-2021-36999?

CVE-2021-36999 has a CVSS score of 7.8 (HIGH). A buffer overflow vulnerability in Huawei smartphones allows remote code execution when users open malicious images. This affects Huawei smartphone users who receive and open specially crafted image files. Attackers can exploit this to execute arbitrary code on the victim's device.

📋 TL;DR

A buffer overflow vulnerability in Huawei smartphones allows remote code execution when users open malicious images. This affects Huawei smartphone users who receive and open specially crafted image files. Attackers can exploit this to execute arbitrary code on the victim's device.

💻 Affected Systems

Products:

Huawei smartphones

Versions: Specific versions not detailed in provided references; check Huawei bulletins for exact affected versions

Operating Systems: HarmonyOS, Android-based Huawei EMUI

Default Config Vulnerable: ⚠️ Yes

Notes: Vulnerability exists in image processing components; affects devices with unpatched software.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete device compromise with attacker gaining full control, data theft, and persistent access.

🟠

Likely Case

Remote code execution leading to malware installation, data exfiltration, or device takeover.

🟢

If Mitigated

Limited impact if images are only opened from trusted sources and device is patched.

🌐 Internet-Facing: MEDIUM

🏢 Internal Only: LOW

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires user interaction (opening malicious image); no public exploit code confirmed.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check Huawei security bulletins for specific patched versions

Vendor Advisory: https://consumer.huawei.com/en/support/bulletin/2021/7/

Restart Required: Yes

Instructions:

1. Check for system updates in device settings. 2. Install latest security update from Huawei. 3. Restart device after update.

🔧 Temporary Workarounds

Disable automatic image loading

all

Prevent automatic loading/display of images in messaging/email apps

Use trusted image sources only

all

Only open images from known, trusted sources

🧯 If You Can't Patch

Restrict image file handling to trusted applications only
Implement network filtering to block suspicious image downloads

🔍 How to Verify

Check if Vulnerable:

Check device software version against Huawei's security bulletin for affected versions

Check Version:

Settings > About phone > Software information

Verify Fix Applied:

Verify device has latest security update installed and version matches patched versions in advisory

📡 Detection & Monitoring

Log Indicators:

Unexpected process crashes in image handling components
Suspicious file access patterns

Network Indicators:

Downloads of unusually formatted image files from untrusted sources

SIEM Query:

Not applicable for consumer mobile devices

📊 Metadata

CVE ID: CVE-2021-36999

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-120

Published: October 28, 2021

Last Updated: November 21, 2024

🔗 References

https://consumer.huawei.com/en/support/bulletin/2021/7/ Vendor Advisory
https://consumer.huawei.com/en/support/bulletin/2021/7/ Vendor Advisory

📤 Share & Export

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🔗 Related Vulnerabilities

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