dbcve.org
Debian LinuxOperating system · Debian

CVE-2021-3909

HIGH · 7.5 CVSS v3.1 Published 2021-11-11
Fix available
A fix is available. Upgrade to 1.3.0 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
OctoRPKI does not limit the length of a connection, allowing for a slowloris DOS attack to take place which makes OctoRPKI wait forever. Specifically, the repository that OctoRPKI sends HTTP requests to will keep the connection open for a day before a response is returned, but does keep drip feeding new bytes to keep the connection alive.

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 · moderate confidence

OctoRPKI lacks HTTP connection timeout limits, allowing attackers to perform a slowloris DoS attack by slowly drip-feeding bytes to keep connections open indefinitely. This exhausts server resources as connections remain waiting for full responses that may take days.

MitigationImplement HTTP client connection and read timeouts to terminate slow or incomplete connections, and add request body size limits to prevent indefinite connection holds.

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
Debian LinuxOperating system
Affected:= 11.0
OctorpkiApplication
Affected:< 1.3.0

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
None
Integrity
None
Availability
High

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

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. Identify if OctoRPKI is installed
    Run 'which octorpki' or check for the binary in common paths such as /usr/bin/octorpki, /usr/local/bin/octorpki, or look for octorpki process running via 'ps aux | grep octorpki'
    Affected if The octorpki binary or process is found on the system
  2. Determine the installed OctoRPKI version
    Run 'octorpki --version' or 'octorpki -v' to retrieve the version number. If using a package manager, also check with 'dpkg -l | grep octorpki' or 'rpm -qa | grep octorpki'
    Affected if The version is less than 1.3.0 (e.g., 1.2.x, 1.1.x, 1.0.x)
  3. Confirm the operating system version on Debian
    Run 'cat /etc/debian_version' or 'lsb_release -a' to identify the Debian release
    Affected if Running Debian Linux version 11.0 with OctoRPKI installed
  4. Check if OctoRPKI is exposed to network connections
    Review the configuration file for HTTP listener settings (typically in /etc/octorpki/config.yaml or similar) and verify network exposure via 'netstat -tlnp | grep octorpki' or 'ss -tlnp | grep octorpki'
    Affected if OctoRPKI is configured to accept HTTP connections from network sources (not limited to localhost)
  5. Verify HTTP timeout configuration exists
    Inspect the OctoRPKI configuration file for any HTTP client timeout, read timeout, or connection timeout settings. Check for fields such as 'timeout', 'read_timeout', 'client_timeout', or similar in the configuration
    Affected if No HTTP timeout settings are defined in the configuration, or timeouts are set to extremely high values (e.g., zero, null, or values exceeding several minutes)

The environment is affected if OctoRPKI version is below 1.3.0 or running on Debian 11.0, and the service is exposed to network HTTP connections with no timeout limits configured.

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 1.3.0 or later
Fixed in 1.3.0
Interim mitigation

Implement HTTP client connection and read timeouts to terminate slow or incomplete connections, and add request body size limits to prevent indefinite connection holds.

Recommended fix High confidence

Version 1.3.0 or later

  1. Check current OctoRPKI version using: dpkg -l octokrpki or rpm -q octokrpki
  2. Update package lists: apt-get update (Debian) or yum check-update (RHEL-based)
  3. Upgrade OctoRPKI to version 1.3.0 or later: apt-get install octokrpki=1.3.0* or yum update octokrpki
  4. Verify the installed version matches or exceeds 1.3.0
  5. Restart the OctoRPKI service if running

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

Fix this in Debian Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-3909 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-3909 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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