dbcve.org
Debian LinuxOperating system · Debian

CVE-2021-3907

CRITICAL · 9.8 CVSS v3.1 Published 2021-11-11
Fix available
A fix is available. Upgrade to 1.3.0 or later.
See remediation →
100/100
Remediation priority · Urgent
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 escape a URI with a filename containing "..", this allows a repository to create a file, (ex. rsync://example.org/repo/../../etc/cron.daily/evil.roa), which would then be written to disk outside the base cache folder. This could allow for remote code execution on the host machine OctoRPKI is running on.

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

OctoRPKI fails to validate or sanitize path traversal sequences ('..') in filenames when processing RPKI repository data fetched via rsync. An attacker controlling a malicious RPKI repository can craft filenames containing '../' sequences (e.g., rsync://example.org/repo/../../etc/cron.daily/evil.roa) to write files outside the intended cache directory. This path traversal can be exploited to place executable content in system directories like cron jobs, achieving remote code execution on the host.

MitigationUpgrade to the patched version of OctoRPKI. Additionally, restrict rsync repository sources to trusted, validated RPKI repositories at the network level to reduce exposure to malicious repositories.

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:= 10.0= 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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Verify OctoRPKI is installed
    Check for the octorpki binary or package using your system's package manager (e.g., dpkg -l | grep octorpki, rpm -qa | grep octorpki, or which octorpki)
    Affected if OctoRPKI is present on the system
  2. Determine installed OctoRPKI version
    Run octorpki --version or query the package manager for the installed version (e.g., dpkg -s octorpki or rpm -qi octorpki)
    Affected if Installed version is less than 1.3.0
  3. Identify rsync as RPKI transport
    Examine the OctoRPKI configuration files or running processes to determine if rsync is configured as the protocol for fetching RPKI repository data
    Affected if rsync is configured as the transport for RPKI repositories
  4. Check Debian version if applicable
    On Debian systems, run cat /etc/debian_version to identify the installed Debian release
    Affected if Running Debian 10.0 or 11.0 with a vulnerable OctoRPKI package installed

You are affected if OctoRPKI version less than 1.3.0 is installed AND rsync is configured as the transport for fetching RPKI repository data, allowing path traversal sequences in filenames to write files outside the intended cache directory.

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

Upgrade to the patched version of OctoRPKI. Additionally, restrict rsync repository sources to trusted, validated RPKI repositories at the network level to reduce exposure to malicious repositories.

Recommended fix High confidence

Octorpki >= 1.3.0

  1. Upgrade Octorpki to version 1.3.0 or later
  2. After upgrading, verify the installation by checking the version with: octorpki --version
  3. Ensure the rsync protocol handler properly validates and sanitizes paths containing '..' sequences before writing files to the cache directory

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-2021-3907 — 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-2021-3907 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