OpenwrtOperating system

CVE-2022-38333

HIGH · 7.5 CVSS v3.1 Published 2022-09-19
Fix available
A fix is available. Upgrade to 21.02.3 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Openwrt before v21.02.3 and Openwrt v22.03.0-rc6 were discovered to contain two skip loops in the function header_value(). This vulnerability allows attackers to access sensitive information via a crafted HTTP request.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OpenWRT before v21.02.3 and v22.03.0-rc6 contains a flaw in the header_value() function where two skip loops can be manipulated via crafted HTTP requests, allowing unauthenticated attackers to read sensitive information from memory or bypass intended access controls.

MitigationUpgrade OpenWRT to v21.02.3, v22.03.0-rc6 or later, or apply the vendor patch that corrects the skip loop logic in header_value(). If upgrading is not immediately feasible, restrict HTTP access to the management interface via firewall rules.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OpenwrtOperating system
Affected:< 21.02.3= 22.03.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OpenWRT version installed
    Run 'cat /etc/os-release' or 'cat /etc/openwrt_version' to see the installed version number
    Affected if Version is below 21.02.3 or equals 22.03.0 (the exact version 22.03.0, not rc versions)
  2. Verify uhttpd web service is running
    Run 'ps | grep uhttpd' or check '/etc/init.d/uhttpd status' to see if the HTTP server is active
    Affected if uhttpd is running and the web interface is accessible (default on port 80 or 443)
  3. Confirm HTTP management interface exposure
    Check '/etc/config/uhttpd' or run 'netstat -tlnp | grep -E "80|443"' to see if HTTP/HTTPS ports are listening on external interfaces
    Affected if The web interface is bound to WAN or otherwise exposed beyond localhost
  4. Verify default access control settings
    Inspect '/etc/config/uhttpd' for 'option listen_http' and 'option listen_https' entries - check if they bind to 0.0.0.0 or specific LAN-only interfaces
    Affected if uhttpd is configured to listen on 0.0.0.0 (all interfaces) rather than 127.0.0.1 (localhost only)

If the installed OpenWRT version is below 21.02.3 or exactly 22.03.0, AND the uhttpd web interface is running and accessible, the environment is vulnerable to unauthenticated memory reads or access control bypass via crafted HTTP requests to header_value().

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 21.02.3 or later
Fixed in 21.02.3
Interim mitigation

Upgrade OpenWRT to v21.02.3, v22.03.0-rc6 or later, or apply the vendor patch that corrects the skip loop logic in header_value(). If upgrading is not immediately feasible, restrict HTTP access to the management interface via firewall rules.

Recommended fix High confidence

OpenWrt v21.02.3 or later stable release

  1. Download the OpenWrt v21.02.3 or later stable firmware image from the official OpenWrt downloads page
  2. Backup current router configuration
  3. Access the router's LuCI web interface or use SSH/Telnet
  4. Navigate to System > Backup / Flash Firmware
  5. Upload and flash the new firmware image
  6. After reboot, restore configuration or perform fresh setup
Caveat Verify router hardware compatibility with target release; custom packages may need reinstallation after upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Openwrt Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,540
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-38333 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-38333 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data