CVE-2017-15736 in SPIP
Summary
by MITRE
Cross-site scripting (XSS) vulnerability (stored) in SPIP before 3.1.7 allows remote attackers to inject arbitrary web script or HTML via a crafted string, as demonstrated by a PGP field, related to prive/objets/contenu/auteur.html and ecrire/inc/texte_mini.php.
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Analysis
by VulDB Data Team • 01/04/2023
The CVE-2017-15736 vulnerability represents a critical stored cross-site scripting flaw in the SPIP content management system prior to version 3.1.7. This vulnerability resides in the handling of user input within the administrative interface, specifically affecting the PGP field processing functionality. The flaw enables remote attackers to execute malicious scripts in the context of other users' browsers, potentially leading to session hijacking, data theft, or unauthorized administrative actions. The vulnerability manifests through the prive/objets/contenu/auteur.html template and the ecrire/inc/texte_mini.php script, which together process and display user-provided content without adequate sanitization measures.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious string containing embedded script code and submits it through the PGP field in the SPIP administrative interface. When other users view the affected content, the malicious script executes in their browser context, allowing attackers to perform actions such as stealing cookies, redirecting users to malicious sites, or modifying page content. The stored nature of this vulnerability means that the malicious payload persists in the database and affects all users who subsequently view the compromised content, unlike reflected XSS where the attack must be delivered directly to the victim. This vulnerability directly maps to CWE-79, which defines the classic cross-site scripting weakness where untrusted data is improperly incorporated into web pages without adequate validation or escaping mechanisms.
The operational impact of CVE-2017-15736 extends beyond simple script execution, as it can be leveraged as a stepping stone for more sophisticated attacks within the SPIP ecosystem. Attackers can use this vulnerability to escalate privileges, access sensitive administrative functions, or exfiltrate data from the CMS. The vulnerability affects the core authentication and content management capabilities of SPIP, potentially compromising entire websites that rely on this platform. According to ATT&CK framework, this vulnerability aligns with T1059.007 for scripting and T1566 for spearphishing with attachments, as it enables attackers to deliver malicious payloads through seemingly legitimate administrative forms. The attack vector specifically targets the web application layer, making it particularly dangerous for organizations that depend on SPIP for content management and user interaction.
Mitigation strategies for CVE-2017-15736 require immediate patching of SPIP installations to version 3.1.7 or later, which includes proper input sanitization and output escaping mechanisms. Organizations should also implement additional defensive measures such as content security policies to prevent execution of unauthorized scripts, regular security audits of user input handling, and monitoring for suspicious administrative activities. The vulnerability underscores the importance of proper input validation and output encoding practices, aligning with security best practices outlined in OWASP Top Ten and NIST cybersecurity guidelines. Administrators should also consider implementing web application firewalls to detect and block malicious payloads, while ensuring that all user inputs are properly sanitized before being stored or displayed in web interfaces.