CVE-2015-7783 in p++BBS
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Let's PHP! p++BBS before 4.10 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 05/24/2018
The CVE-2015-7783 vulnerability represents a critical cross-site scripting flaw discovered in the Let's PHP! p++BBS software version 4.10 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 issues. The vulnerability allows remote attackers to inject malicious scripts or HTML content into web pages viewed by other users, creating a significant threat to web application integrity and user security. The unspecified vectors indicate that the attack could occur through multiple entry points within the application's input handling mechanisms.
The technical flaw stems from insufficient input validation and output encoding within the p++BBS platform. When users submit data through various forms, comments, or other interactive elements, the application fails to properly sanitize or escape the input before rendering it in web pages. This allows attackers to craft malicious payloads that get executed in the context of other users' browsers. The vulnerability is particularly concerning because it affects the core functionality of a bulletin board system where user-generated content is abundant and frequently displayed to other users. Attackers could exploit this weakness to execute scripts that steal session cookies, perform unauthorized actions on behalf of users, or redirect them to malicious websites.
The operational impact of this vulnerability extends beyond simple data theft or defacement. Attackers could leverage this XSS flaw to establish persistent access to user accounts by stealing authentication tokens and session identifiers. The vulnerability creates a pathway for more sophisticated attacks such as credential theft, session hijacking, and data exfiltration. In a bulletin board environment, where users frequently engage with content and interact with each other, the potential for widespread exploitation is significant. The attack could compromise multiple user accounts simultaneously, leading to unauthorized access to private messages, personal information, and potentially administrative privileges if the vulnerability affects administrator interfaces.
Mitigation strategies for CVE-2015-7783 should focus on implementing robust input validation and output encoding mechanisms. Organizations should ensure that all user-provided data is properly sanitized before being rendered in web pages, utilizing context-appropriate escaping techniques for different output contexts such as HTML, JavaScript, and CSS. The recommended solution involves upgrading to version 4.10 or later of the p++BBS software, which contains the necessary security patches to address the vulnerability. Additionally, implementing Content Security Policy headers, using secure coding practices, and conducting regular security testing can significantly reduce the risk of exploitation. From an ATT&CK framework perspective, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) techniques, as attackers could use the vulnerability to deliver malicious payloads and establish initial access through social engineering campaigns. The vulnerability also aligns with T1071.001 (Application Layer Protocol: Web Protocols) as it exploits weaknesses in web application protocols and data handling mechanisms.