CVE-2025-1735 is a vulnerability in the PHP language's PostgreSQL escaping functions (pgsql and pdo_pgsql) affecting versions 8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, and 8.4.*. The issue arises because these escaping functions do not properly check whether the underlying PostgreSQL quoting functions return errors when processing input strings. If the PostgreSQL server rejects a string as invalid during the escaping process, PHP does not handle this error correctly, which can lead to application crashes. This improper neutralization of special elements used in SQL commands is categorized under CWE-89 (SQL Injection) and CWE-476 (NULL Pointer Dereference), although the vulnerability primarily results in denial of service rather than direct SQL injection exploitation. The CVSS v3.1 score is 5.9 (medium severity), reflecting that the vulnerability can be exploited remotely without authentication or user interaction but requires high attack complexity. The impact is mainly on availability, as attackers can cause PHP applications interfacing with PostgreSQL to crash by sending crafted input that triggers the error condition. No known exploits have been reported in the wild, but the vulnerability poses a risk to web applications and services relying on vulnerable PHP versions with PostgreSQL backends. The vulnerability was publicly disclosed on July 13, 2025, and no official patches are linked in the provided data, but updated PHP versions beyond the specified vulnerable releases are expected to address the issue.

For European organizations, this vulnerability primarily threatens the availability of web applications and services that use vulnerable PHP versions with PostgreSQL databases. A successful exploitation can cause application crashes, leading to denial of service conditions that disrupt business operations, customer access, and internal workflows. This can be particularly damaging for sectors relying heavily on PHP and PostgreSQL, such as e-commerce, government portals, financial services, and healthcare systems. While the vulnerability does not directly compromise data confidentiality or integrity, the resulting downtime can lead to reputational damage, financial losses, and compliance issues under regulations like GDPR if service interruptions affect data processing or availability commitments. Organizations with high-availability requirements or critical infrastructure services are at elevated risk. The lack of known exploits reduces immediate threat, but the medium severity and ease of remote exploitation without authentication warrant proactive mitigation to prevent potential future attacks or automated scanning attempts.

1. Upgrade PHP to the latest patched versions beyond 8.1.33, 8.2.29, 8.3.23, or the fixed 8.4.* release as soon as they become available. 2. Implement strict input validation and sanitization on all user inputs before they reach database escaping functions to minimize malformed or malicious strings. 3. Enhance error handling in PHP applications to detect and gracefully manage errors returned by PostgreSQL quoting functions, preventing crashes. 4. Monitor application logs and PostgreSQL logs for unusual error patterns or crashes that may indicate attempted exploitation. 5. Employ Web Application Firewalls (WAFs) with rules targeting malformed SQL inputs or known attack vectors against PostgreSQL. 6. Conduct regular security assessments and penetration testing focusing on database interaction layers. 7. For critical services, consider deploying failover or redundancy mechanisms to maintain availability during potential crash events. 8. Educate developers and DevOps teams about this vulnerability and best practices for secure database interaction and error handling.