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MaharaApplication

CVE-2021-40848

HIGH · 7.8 CVSS v3.1 Published 2021-11-03
Fix available
A fix is available. Upgrade to 20.04.5 / 20.10.3 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
In Mahara before 20.04.5, 20.10.3, 21.04.2, and 21.10.0, exported CSV files could contain characters that a spreadsheet program could interpret as a command, leading to execution of a malicious string locally on a device, aka CSV injection.

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

Mahara before the specified versions contains a CSV injection vulnerability where exported CSV files can include spreadsheet formula characters (such as =, +, -, @) that cause the spreadsheet application to interpret the content as a formula, potentially executing arbitrary commands on the victim's local machine when the file is opened.

MitigationImplement output encoding for CSV exports by escaping or removing formula-initiating characters (=, +, -, @, tab, carriage return) from user-supplied data, or prefixing values with a single quote to force text interpretation in spreadsheet programs.

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
MaharaApplication
Affected:< 20.04.5>= 20.10.0, < 20.10.3>= 21.04.0, < 21.04.2= 21.10.0

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 Mahara version
    Locate the version file (typically version.php in the htdocs directory) or access the admin panel's 'Site options' > 'Version' page to determine the installed Mahara version number.
    Affected if The installed version falls within < 20.04.5, >= 20.10.0 but < 20.10.3, >= 21.04.0 but < 21.04.2, or equals 21.10.0.
  2. Confirm CSV export functionality is accessible
    Verify that export features are enabled in Mahara by checking the 'Export' options in the admin panel or by attempting to export data (e.g., user portfolios, submitted artifacts, or institutional data) to CSV format.
    Affected if CSV export functionality is available and users can generate CSV files from Mahara data.
  3. Test exported CSV for formula injection characters
    Export a CSV file containing user-supplied data (such as a portfolio or user profile export), then open the CSV in a text editor to inspect whether cells beginning with =, +, -, @, tab, or carriage return characters are present without encoding or escaping.
    Affected if The exported CSV contains unescaped formula-initiating characters (=, +, -, @) in data fields from user input.

You are affected if your Mahara version is in the vulnerable range and CSV export is used, with unescaped formula characters present in exported CSV files.

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 20.04.5 / 20.10.3 / 21.04.2 or later
Fixed in 20.04.520.10.321.04.2
Interim mitigation

Implement output encoding for CSV exports by escaping or removing formula-initiating characters (=, +, -, @, tab, carriage return) from user-supplied data, or prefixing values with a single quote to force text interpretation in spreadsheet programs.

Recommended fix High confidence

20.04.5, 20.10.3, 21.04.2, or 21.10.1+ (choose based on your current branch)

  1. 1. Identify the current Mahara version by checking the admin interface or the lib/version.php file
  2. 2. Determine which upgrade path applies based on your current version: if < 20.04.5 upgrade to 20.04.5; if >= 20.10.0 and < 20.10.3 upgrade to 20.10.3; if >= 21.04.0 and < 21.04.2 upgrade to 21.04.2; if 21.10.0 upgrade to 21.10.1 or later
  3. 3. Perform a complete backup of the Mahara database and filesystem
  4. 4. Put the site into maintenance mode via the admin interface or config.php
  5. 5. Download the appropriate fixed version from https://launchpad.net/mahara/+download
  6. 6. Extract the new version and replace the existing Mahara files, preserving the config.php and any custom local changes
  7. 7. Run the upgrade script via the web interface (visit the site URL) or CLI (php admin/cli/upgrade.php)
  8. 8. Clear all caches and verify the upgrade was successful
Caveat Check release notes for your specific upgrade path; minor version upgrades within the same release series typically have minimal breaking changes

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

Fix this in Mahara Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2021-40848 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