CVE-2024-35498 is a cross-site scripting (XSS) vulnerability identified in Grav CMS version 1.7.45. XSS vulnerabilities arise when an application does not properly sanitize user-supplied input, allowing attackers to inject malicious scripts into web pages viewed by other users. In this case, the vulnerability permits attackers to craft payloads that execute arbitrary JavaScript or HTML in the context of the vulnerable Grav CMS site. This can lead to session hijacking, defacement, or redirection to malicious sites. The CVSS 3.1 vector indicates the attack is network exploitable (AV:N), requires low attack complexity (AC:L), no privileges (PR:N), but requires user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the vulnerable component. The impact affects confidentiality and integrity (C:L/I:L) but not availability (A:N). No known exploits have been reported yet, but the vulnerability is publicly disclosed and should be treated seriously. Grav CMS is a modern flat-file CMS popular among developers for its simplicity and flexibility, used worldwide for websites and blogs. The lack of a patch link suggests a fix may still be pending or not yet widely distributed. The CWE-79 classification confirms this is a classic XSS issue. Organizations running Grav CMS should review input handling and consider temporary mitigations until an official patch is released.

The primary impact of CVE-2024-35498 is the potential compromise of user confidentiality and integrity on websites running vulnerable versions of Grav CMS. Exploitation can lead to theft of session cookies, enabling attackers to impersonate users or administrators, potentially leading to unauthorized access. Attackers may also manipulate web content, inject phishing forms, or redirect users to malicious sites, undermining user trust and damaging organizational reputation. While availability is not directly affected, the indirect consequences of successful attacks can include loss of customer confidence and potential regulatory penalties if user data is compromised. Given Grav CMS's use in small to medium-sized websites, the impact may be more pronounced for organizations lacking robust security monitoring. The requirement for user interaction means phishing or social engineering may be used to trigger the exploit, increasing the risk to end users. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as public disclosure may prompt attackers to develop exploits.

Organizations should immediately assess their Grav CMS installations to determine if version 1.7.45 or earlier vulnerable versions are in use. Until an official patch is released, implement strict input validation and sanitization on all user-supplied data to prevent script injection. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Enable HTTP-only and Secure flags on cookies to reduce the risk of session hijacking. Educate users and administrators about the risks of clicking untrusted links or interacting with suspicious content that could trigger the XSS payload. Monitor web server logs and application behavior for unusual requests or script injections. Consider deploying Web Application Firewalls (WAFs) with rules targeting XSS attack patterns specific to Grav CMS. Stay informed about updates from Grav CMS developers and apply patches promptly once available. Conduct regular security audits and penetration testing focused on input handling and client-side script execution.