1. Mass Exploitation of (Un)authenticated Zimbra RCE: CVE-2022-27925

    [Note: Volexity has reported all findings in this post to Zimbra. Where an existing contact was known, Volexity has notified local CERTs of compromised Zimbra instances in their constituency. The newest versions of Zimbra are patched for both the RCE vulnerability and authentication bypass vulnerabilities described in this blog.] In July and early August 2022, Volexity worked on multiple incidents where the victim organization experienced serious breaches to their Zimbra Collaboration Suite (ZCS) email servers. Volexity’s investigations uncovered evidence indicating the likely cause of these breaches was exploitation of CVE-2022-27925, a remote-code-execution (RCE) vulnerability in ZCS. This initial CVE was patched by Zimbra in March 2022 in 8.8.15P31 and 9.0.0P24. Figure 1. Description of CVE-2022-27925 from the NIST website Initial research into the vulnerability did not uncover any public exploit code, but since a patch had been available for several months, it was reasonable that exploit code could have been […]

  2. Zero-Day Exploitation of Atlassian Confluence

    UPDATE: On June 3, 2022, Atlassian updated its security advisory with new information regarding a fix for Confluence Server and Data Center to address CVE-2022-26134. Users are encouraged to update immediately to mitigate their risk. Additional observations after publication of this blog post have been shared here, with guidance on how to verify if you have been impacted by unauthorized access.  Over the Memorial Day weekend in the United States, Volexity conducted an incident response investigation involving two Internet-facing web servers belonging to one of its customers that were running Atlassian Confluence Server software. The investigation began after suspicious activity was detected on the hosts, which included JSP webshells being written to disk. Volexity immediately used Volexity Surge Collect Pro to collect system memory and key files from the Confluence Server systems for analysis. After a thorough review of the collected data, Volexity was able to determine the server compromise stemmed from […]

  3. Operation EmailThief: Active Exploitation of Zero-day XSS Vulnerability in Zimbra

    [UPDATE] On February 4, 2022, Zimbra provided an update regarding this zero-day exploit vulnerability and reported that a hotfix for 8.8.15 P30 would be available on February 5, 2022. This vulnerability was later assigned CVE-2022-24682 and was fixed in version 8.8.15P30 Update 2 of Zimbra Collaboration Suite. In December 2021, through its Network Security Monitoring service, Volexity identified a series of targeted spear-phishing campaigns against one of its customers from a threat actor it tracks as TEMP_Heretic. Analysis of the emails from these spear phishing campaigns led to a discovery: the attacker was attempting to exploit a zero-day cross-site scripting (XSS) vulnerability in the Zimbra email platform. Zimbra is an open source email platform often used by organizations as an alternative to Microsoft Exchange. The campaigns came in multiple waves across two attack phases. The initial phase was aimed at reconnaissance and involved emails designed to simply track if a target […]