a-blog cms Zero-Day Vulnerability

A critical security vulnerability has been discovered in a-blog cms, a web content management system developed by appleple inc.. The Japan Computer Emergency Response Team/Coordination Center (JPCERT/CC) has issued a vulnerability note regarding CVE-2025-31103, highlighting an “untrusted data deserialization vulnerability“. This flaw poses a significant risk to web servers running affected versions of the software.
Vulnerability impact ->
The vulnerability lies in how a-blog cms handles untrusted data. An attacker can exploit this weakness by “processing a specially crafted request“. Successful exploitation could allow the attacker to “store arbitrary files on the server where the product is running“. The consequences of this are severe, as it “can be leveraged to execute an arbitrary script on the server“. This level of access could lead to website defacement, data theft, or complete server compromise.
Which Versions are Affected?
The following versions of a-blog cms are vulnerable:
a-blog cms versions prior to Ver.3.1.37 (Ver.3.1.x series)a-blog cms versions prior to Ver.3.0.41 (Ver.3.0.x series)a-blog cms versions prior to Ver.2.11.70 (Ver.2.11.x series)a-blog cms versions prior to Ver.2.10.58 (Ver.2.10.x series)a-blog cms versions prior to Ver.2.9.46 (Ver.2.9.x series)a-blog cms versions prior to Ver.2.8.80 (Ver.2.8.x series)It’s crucial to note that, “according to the developer, a-blog cms Ver.2.7 and earlier versions, which are now unsupported, are affected as well“.
Exploitation in the Wild
“The developer states that attacks exploiting the vulnerability has been observed on a-blog cms Ver.2.8.x series or later“. This indicates that malicious actors are actively attempting to take advantage of this vulnerability, making immediate action essential.
Mitigation and Solution
The primary solution is to “update the software to the latest version according to the information provided by the developer“. Applying the latest patch will eliminate the vulnerability and secure your web server.
However, if an immediate update is not possible, “the developer recommends to apply the workaround to mitigate the impact of this vulnerability“.
Conclusion
The CVE-2025-31103 vulnerability in a-blog cms presents a serious risk to web servers. The potential for arbitrary file storage and script execution could have devastating consequences. Site administrators and security teams must prioritize updating their a-blog cms installations or applying the recommended workaround to protect their systems from exploitation. The fact that attacks have already been observed underscores the urgency of this situation.