CVE-2025-51735: Unveiling a CSV Formula Injection Vulnerability in HCL Unica 12.0.0

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Overview

CVE-2025-51735 describes a CSV (Comma Separated Values) formula injection vulnerability found in HCL Technologies Ltd.’s Unica version 12.0.0. This vulnerability allows an attacker to inject malicious formulas into CSV files generated by the application. When these files are opened by a user in spreadsheet software (like Microsoft Excel or Google Sheets), the injected formulas can be executed, potentially leading to information disclosure, arbitrary code execution, or other malicious actions.

Technical Details

CSV injection occurs when user-controlled data is included in a CSV file without proper sanitization or escaping. Spreadsheet applications interpret certain strings as formulas, beginning with characters such as ‘=’, ‘@’, ‘+’, or ‘-‘. By crafting specific input containing these characters followed by malicious commands (e.g., `=cmd|’/C calc’!A0`), an attacker can exploit this behavior.

In HCL Unica 12.0.0, if the application generates CSV files containing unsanitized data provided by users (through forms, APIs, or other input mechanisms), it becomes susceptible to this type of attack. The vulnerability lies in the insufficient validation or escaping of these characters within the exported CSV data.

CVSS Analysis

While the CVE entry currently lists the severity and CVSS score as “N/A,” it’s crucial to assess the actual risk based on the specific context of the HCL Unica deployment. A more accurate CVSS score would depend on factors such as:

  • **Attack Vector:** How easily can an attacker inject malicious data? (e.g., local network, public internet)
  • **Attack Complexity:** How much specialized knowledge or effort is required to exploit the vulnerability?
  • **Privileges Required:** What level of access does an attacker need to inject the malicious data?
  • **User Interaction:** Does the user need to open the malicious CSV file for the exploit to be triggered?
  • **Scope:** Does the vulnerability affect only the user opening the CSV, or does it potentially impact other parts of the system?
  • **Confidentiality Impact:** Could sensitive information be leaked?
  • **Integrity Impact:** Could data be modified or corrupted?
  • **Availability Impact:** Could the system become unavailable?

Given the potential for arbitrary code execution via spreadsheet formulas, it is likely that if formally scored, this vulnerability could receive a CVSS score within the Medium to High range depending on the factors listed above.

Possible Impact

Successful exploitation of this CSV injection vulnerability could lead to several negative consequences:

  • **Information Disclosure:** An attacker could extract sensitive data from the user’s system or network.
  • **Arbitrary Code Execution:** Malicious formulas can execute arbitrary commands on the user’s machine, potentially installing malware or compromising the system.
  • **Credential Theft:** Attackers could potentially steal user credentials stored on the system.
  • **Data Manipulation:** The attacker could modify or delete data within the spreadsheet application or other connected systems.
  • **Phishing Attacks:** The vulnerability can be used to deliver convincing phishing attacks disguised as legitimate data.

Mitigation and Patch Steps

To mitigate the risk posed by CVE-2025-51735, the following steps are recommended:

  1. **Apply the Patch:** Contact HCL Technologies Ltd. to obtain and apply the official patch or upgrade to a version of Unica where this vulnerability has been addressed. This is the most effective solution.
  2. **Input Validation:** Implement robust input validation on all data sources used to generate CSV files. Sanitize or escape any characters that could be interpreted as formula delimiters (e.g., ‘=’, ‘@’, ‘+’, ‘-‘).
  3. **Output Encoding:** Properly encode the CSV data to prevent formula injection. For example, you can prefix potentially dangerous cells with a single quote (‘).
  4. **User Education:** Educate users about the risks of opening CSV files from untrusted sources and the potential for formula injection attacks.
  5. **Restrict Spreadsheet Functionality (User-Side):** Users can configure their spreadsheet software to disable automatic formula execution or to prompt before executing potentially dangerous functions. However, this is a client-side mitigation and does not address the underlying vulnerability.

References

CVE-2025-51735 Reference Gist
NIST NVD Entry for CVE-2025-51735 (If available after publication)


HCL Unica Official Website

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