CVE-2015-0871 in Guestbook
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Mrs. Shiromuku Perl CGI shiromuku(u1)GUESTBOOK 1.62 and earlier allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 04/10/2018
The CVE-2015-0871 vulnerability represents a critical cross-site scripting flaw within the Mrs. Shiromuku Perl CGI guestbook application version 1.62 and earlier. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The vulnerability stems from insufficient input validation and output encoding mechanisms within the application's processing of user-supplied data. Attackers can exploit this weakness by injecting malicious scripts or HTML code through unspecified vectors within the guestbook functionality, potentially compromising user sessions and data integrity. The vulnerability exists because the application fails to properly sanitize or escape user input before rendering it in web pages, creating an environment where malicious code can execute in the context of other users' browsers.
The technical exploitation of this vulnerability occurs when an attacker submits malicious input through the guestbook submission interface or other interaction points within the application. The unspecified vectors suggest that multiple entry points within the application could be compromised, potentially including form fields, URL parameters, or other user-controllable inputs. When legitimate users view the affected pages containing the injected malicious content, their browsers execute the embedded scripts, which can lead to session hijacking, credential theft, or redirection to malicious sites. The Perl CGI implementation likely processes user input without adequate sanitization, allowing attackers to inject script tags or other malicious payloads that persist in the application's data storage and are subsequently served to other users.
The operational impact of CVE-2015-0871 extends beyond simple data corruption or user inconvenience. This vulnerability enables attackers to perform session hijacking attacks, potentially gaining unauthorized access to user accounts and administrative functions. The persistent nature of the XSS vulnerability means that once exploited, malicious scripts can continue to affect users until the application is patched or the compromised data is manually removed. Organizations using this vulnerable guestbook application face significant risks including data breaches, loss of user trust, and potential compliance violations under data protection regulations such as GDPR or HIPAA. The vulnerability also provides a potential foothold for more sophisticated attacks, as attackers can use the XSS payload to establish persistent access or escalate privileges within the affected environment.
Mitigation strategies for CVE-2015-0871 should focus on immediate application patching and input validation improvements. Organizations must upgrade to the latest version of the Mrs. Shiromuku guestbook application where the vulnerability has been addressed through proper input sanitization and output encoding mechanisms. In the interim, implementing proper input validation techniques including whitelisting of acceptable characters, comprehensive output encoding for HTML, and the use of Content Security Policy headers can provide temporary protection. The application should implement proper sanitization of all user inputs before storage and rendering, following the principle of least privilege in input handling. Additionally, regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other web applications within the organization's infrastructure. Security monitoring should be enhanced to detect unusual patterns of user input that may indicate attempted exploitation of XSS vulnerabilities, aligning with ATT&CK technique T1059.002 for command and scripting interpreter. Organizations should also consider implementing web application firewalls and security headers to provide additional layers of protection against such attacks, as recommended in NIST SP 800-53 security controls for web application security.