CVE-2022-28977 is a medium-severity open redirect vulnerability affecting multiple versions of Liferay Portal (7.3.1 through 7.4.2) and Liferay DXP (7.0 fix pack 91 through 101, 7.1 fix pack 17 through 25, 7.2 fix pack 5 through 14, and 7.3 before service pack 3). The vulnerability arises from improper validation in the HtmlUtil.escapeRedirect method, which is intended to sanitize redirect URLs to prevent malicious redirection. However, attackers can bypass this validation by using multiple forward slashes in the URL parameters, specifically the 'redirect' parameter, the 'FORWARD_URL' parameter, and other parameters that rely on HtmlUtil.escapeRedirect. This allows remote attackers to craft URLs that redirect users to arbitrary external sites. The vulnerability is classified under CWE-601 (URL Redirection to Untrusted Site ('Open Redirect')). The CVSS v3.1 base score is 6.1, indicating a medium severity level, with attack vector being network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and low impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). No known exploits in the wild have been reported. The vulnerability can be leveraged in phishing campaigns or social engineering attacks to redirect users to malicious websites, potentially leading to credential theft, malware downloads, or other malicious activities. Since the vulnerability affects multiple widely used versions of Liferay Portal and DXP, organizations using these platforms are at risk if they have not applied patches or mitigations.

For European organizations, the impact of CVE-2022-28977 can be significant, especially for those relying on Liferay Portal or Liferay DXP for their web portals, intranets, or customer-facing applications. The open redirect vulnerability can be exploited by attackers to redirect legitimate users to malicious external sites, facilitating phishing attacks, credential harvesting, or malware distribution. This can lead to reputational damage, loss of customer trust, and potential regulatory repercussions under GDPR if personal data is compromised as a result of subsequent attacks. Additionally, since the scope is changed (S:C), the vulnerability could be used to bypass same-origin policies in some scenarios, potentially enabling further exploitation. The requirement for user interaction means that attackers must entice users to click on crafted URLs, which is common in phishing campaigns. The medium severity indicates that while the vulnerability is not critical, it still poses a meaningful risk that should be addressed promptly to prevent exploitation. Organizations in sectors with high web portal usage, such as government, finance, healthcare, and education, may face higher risks due to the sensitivity of their data and the critical nature of their services.

To mitigate CVE-2022-28977, European organizations should: 1) Apply official patches or upgrade to fixed versions of Liferay Portal and Liferay DXP as soon as they become available from the vendor. 2) Implement strict input validation and sanitization on all redirect parameters beyond relying solely on HtmlUtil.escapeRedirect, including normalization of URLs to remove multiple forward slashes and other bypass techniques. 3) Employ allowlists for redirect URLs to ensure redirection only occurs to trusted internal domains or explicitly approved external URLs. 4) Use Content Security Policy (CSP) headers to restrict navigation and framing to trusted domains, reducing the impact of malicious redirects. 5) Educate users and staff about phishing risks and encourage cautious behavior when clicking on links, especially those received via email or untrusted sources. 6) Monitor web server logs and application logs for unusual redirect patterns or spikes in redirect parameter usage that could indicate exploitation attempts. 7) Consider implementing web application firewalls (WAFs) with rules to detect and block suspicious redirect URLs containing multiple forward slashes or known bypass patterns. These steps collectively reduce the risk of exploitation and limit the potential damage if an attack occurs.