dbcve.org
Debian LinuxOperating system · Debian

CVE-2019-3463

CRITICAL · 9.8 CVSS v3.1 Published 2019-02-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Insufficient sanitization of arguments passed to rsync can bypass the restrictions imposed by rssh, a restricted shell that should restrict users to perform only rsync operations, resulting in the execution of arbitrary shell commands.

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

rssh (restricted shell for rsync) contains an argument sanitization flaw that allows attackers to escape the restricted shell and execute arbitrary commands by passing specially crafted arguments to rsync.

MitigationUpgrade rssh to the patched version or apply available security updates. If no patch is available, implement additional network-level access controls or consider alternative restricted shell solutions.

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:= 8.0= 9.0
FedoraOperating system
Affected:= 29= 30= 31
Ubuntu LinuxOperating system
Affected:= 14.04= 16.04= 18.04= 18.10
RsshApplication
Affected:= 2.3.4

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 rssh is installed
    Run 'which rssh' or check your package manager: 'dpkg -l | grep rssh' (Debian/Ubuntu) or 'rpm -qa | grep rssh' (Fedora/RHEL)
    Affected if rssh is not installed on the system, the vulnerability does not apply
  2. Determine installed rssh version
    Run 'rssh --version' or inspect the package version via your package manager (dpkg -l or rpm -qi rssh)
    Affected if The installed version matches one of the affected versions: 2.3.4 (Pizzashack), or any version on Debian 8.0/9.0, Fedora 29/30/31, Ubuntu 14.04/16.04/18.04/18.10 systems
  3. Confirm rsync is allowed in rssh configuration
    Inspect the rssh configuration file at /etc/rssh.conf and look for a line containing 'allowrsync' or check that 'rsync' is not commented out in the configuration
    Affected if rsync is explicitly allowed in the rssh configuration, meaning users can invoke rsync through the restricted shell
  4. Identify users with rssh as their login shell
    Check /etc/passwd for users with /usr/bin/rssh or /bin/rssh listed as their shell: 'grep rssh /etc/passwd'
    Affected if Any system accounts or user accounts are configured to use rssh as their restricted shell, creating a potential attack vector

A system is affected if rssh is installed with an unpatched version, rsync is enabled in the configuration, and users have rssh configured as their shell to access rsync services.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade rssh to the patched version or apply available security updates. If no patch is available, implement additional network-level access controls or consider alternative restricted shell solutions.

Recommended fix High confidence

rssh version 2.3.4.45 or later / distribution-specific security update

  1. Update the rssh package to the latest version available in your distribution's security repository
  2. For Debian: Run 'apt-get update && apt-get install rssh' to get the patched version
  3. For Ubuntu: Run 'apt-get update && apt-get install rssh' to get the patched version
  4. For Fedora: Run 'dnf update rssh' to get the patched version
  5. Verify the installed version is patched (check that rsync arguments are properly sanitized)

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

Fix this in Debian Linux Scoped from the published advisory
  • Consultation3.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,950
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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-2019-3463 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