CVE-2025-9100 is a security vulnerability identified in version 1.0.0 of the zhenfeng13 My-Blog software, specifically within the /blog/comment endpoint of the Frontend Blog Article Comment Handler component. The flaw enables an attacker to bypass authentication through a capture-replay attack. This means that an adversary can intercept legitimate authentication tokens or session data transmitted during a valid user session and replay these captured messages to gain unauthorized access without needing valid credentials or user interaction. The vulnerability is remotely exploitable, requiring no privileges or authentication, and no user interaction is necessary, making it relatively easy for attackers to leverage. The CVSS 4.0 base score is 6.9, indicating a medium severity level, with the vector highlighting network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and partial impact on integrity (VI:L) but no impact on confidentiality or availability. The vulnerability does not involve scope changes or security requirements alterations. Although no known exploits are currently observed in the wild, the public disclosure of the exploit increases the risk of exploitation. The lack of available patches or mitigation links suggests that users of this software version remain vulnerable until a fix is issued. The core technical issue lies in improper handling of authentication tokens or session validation in the comment submission process, allowing replayed authentication data to bypass normal security checks.

For European organizations using zhenfeng13 My-Blog 1.0.0, this vulnerability poses a significant risk of unauthorized access to blog management or user accounts, potentially allowing attackers to post unauthorized comments, manipulate content, or escalate privileges if combined with other vulnerabilities. This could lead to reputational damage, misinformation dissemination, or unauthorized data exposure. Since the attack requires no authentication or user interaction and can be performed remotely, the threat surface is broad. Organizations relying on this blogging platform for public-facing content or internal communications may face integrity compromises of their published information. Additionally, if the blog platform integrates with other internal systems or shares authentication tokens, the risk could extend beyond the blog itself. The medium severity rating suggests moderate impact, but the ease of exploitation and lack of required privileges elevate the urgency for mitigation. European entities with compliance obligations around data integrity and access control (e.g., GDPR) must consider the potential regulatory implications of unauthorized access incidents stemming from this vulnerability.

Given the absence of official patches, European organizations should implement immediate compensating controls. These include deploying web application firewalls (WAFs) configured to detect and block replayed authentication tokens or suspicious repeated requests to the /blog/comment endpoint. Enabling HTTPS with strict transport security can reduce the risk of token capture during transmission. Organizations should also monitor logs for unusual comment submission patterns indicative of replay attacks. If feasible, disabling or restricting access to the vulnerable comment functionality until a patch is available can reduce exposure. Implementing additional authentication mechanisms such as CAPTCHA or multi-factor authentication on comment submission may help mitigate automated replay attempts. Reviewing and enhancing session management to include nonce or timestamp validation can prevent replay attacks. Finally, organizations should maintain close contact with the vendor for patch releases and apply updates promptly once available.