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Debian LinuxOperating system · Debian

CVE-2019-19450

CRITICAL · 9.8 CVSS v3.1 Published 2023-09-20
Fix available
A fix is available. Upgrade to 3.5.31 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
paraparser in ReportLab before 3.5.31 allows remote code execution because start_unichar in paraparser.py evaluates untrusted user input in a unichar element in a crafted XML document with '<unichar code="' followed by arbitrary Python code, a similar issue to CVE-2019-17626.

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

The paraparser component in ReportLab before version 3.5.31 contains a code injection vulnerability in the start_unichar function. By supplying malicious Python code within the 'code' attribute of a <unichar> XML element, an attacker can achieve arbitrary code execution on the target system. This is due to the function evaluating untrusted input directly rather than treating it as literal character data.

MitigationUpgrade ReportLab to version 3.5.31 or later. If upgrading is not immediately feasible, disable or restrict processing of untrusted XML documents through the paraparser component as a temporary workaround.

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
ReportlabApplication
Affected:< 3.5.31

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. Identify installed ReportLab version
    Run 'pip show reportlab' or check your package manager for the installed reportlab version. On Debian systems, check 'dpkg -l | grep reportlab' or look in /usr/lib/python3*/dist-packages/reportlab/__init__.py for the version string.
    Affected if The installed version is lower than 3.5.31 (e.g., 3.5.30, 3.5.29, etc.)
  2. Verify paraparser module is in use
    Search your codebase for imports of 'reportlab.lib.utils' or direct imports of 'paraparser'. Run 'grep -r "from reportlab" your_app_path/' or check if your application processes XML using ReportLab's xmlLib.
    Affected if Your application imports or uses the paraparser component to process XML documents
  3. Confirm XML input can include <unichar> elements
    Review any code that passes XML data to ReportLab's parser. Look for patterns where user-supplied or external XML documents are processed through functions like 'Paragraph' or 'setFont' that may internally use the XML parser.
    Affected if Your application processes untrusted XML documents through ReportLab's XML handling functions
  4. Check if code attribute evaluation is possible
    Examine the data flow of any XML documents processed by paraparser. Determine if the 'code' attribute within <unichar> tags could contain Python expression syntax that would be evaluated by the vulnerable start_unichar function.
    Affected if Your application accepts or processes XML containing <unichar> tags with a 'code' attribute from untrusted sources

You are affected if you run ReportLab version below 3.5.31 AND your application uses the paraparser component to process untrusted XML documents containing <unichar> elements with a 'code' attribute.

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 3.5.31 or later
Fixed in 3.5.31
Interim mitigation

Upgrade ReportLab to version 3.5.31 or later. If upgrading is not immediately feasible, disable or restrict processing of untrusted XML documents through the paraparser component as a temporary workaround.

Recommended fix High confidence

ReportLab 3.5.31

  1. Check the currently installed ReportLab version using: pip show reportlab or pip list | grep reportlab
  2. Upgrade ReportLab to version 3.5.31 or later using: pip install --upgrade reportlab>=3.5.31
  3. If using Debian's package manager, update via: apt-get update && apt-get install python3-reportlab (or check for available fixed packages)
  4. Verify the upgrade was successful by checking the installed version: pip show reportlab
  5. Test the application to ensure functionality is intact after the upgrade

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
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
Get the upgrade done

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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-2019-19450 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