Zimbra

Pierluigi Paganini October 07, 2025
U.S. CISA adds Synacor Zimbra Collaboration Suite (ZCS) flaw to its Known Exploited Vulnerabilities catalog

U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds Synacor Zimbra Collaboration Suite (ZCS) flaw to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added Synacor Zimbra Collaboration Suite (ZCS) flaw, tracked as CVE-2025-27915, to its Known Exploited Vulnerabilities (KEV) catalog. CVE-2025-27915 is a stored XSS flaw in Zimbra Collaboration Suite (versions 9.0–10.1) […]

Pierluigi Paganini October 06, 2025
Zimbra users targeted in zero-day exploit using iCalendar attachments

Threat actors exploited a Zimbra zero-day via malicious iCalendar (.ICS) files used to deliver attacks through calendar attachments. StrikeReady researchers discovered that threat actors exploited the vulnerability CVE-2025-27915 in Zimbra Collaboration Suite in zero-day attacks using malicious iCalendar (.ICS) files. These files, used to share calendar data, were weaponized to deliver JavaScript payloads to targeted […]

Pierluigi Paganini November 16, 2023
Zimbra zero-day exploited to steal government emails by four groups

Google TAG revealed that threat actors exploited a Zimbra Collaboration Suite zero-day (CVE-2023-37580) to steal emails from governments. Google Threat Analysis Group (TAG) researchers revealed that a zero-day vulnerability, tracked as CVE-2023-37580 (CVSS score: 6.1), in the Zimbra Collaboration email software was exploited by four different threat actors to steal email data, user credentials, and authentication tokens […]

Pierluigi Paganini August 18, 2023
Massive phishing campaign targets users of the Zimbra Collaboration email server

A massive social engineering campaign is targeting users of the Zimbra Collaboration email server to steal their login credentials. ESET researchers uncovered a mass-spreading phishing campaign targeting users of the Zimbra Collaboration email server since April 2023. Zimbra Collaboration is an open-core collaborative software platform. The campaign is still ongoing and is targeting a wide range of […]

Pierluigi Paganini July 13, 2023
Zimbra urges customers to manually fix actively exploited zero-day reported by Google TAG

Zimbra has released updates to address a zero-day vulnerability actively exploited in attacks aimed at Zimbra Collaboration Suite (ZCS) email servers. Zimbra urges customers to manually install updates to fix a zero-day vulnerability that is actively exploited in attacks against Zimbra Collaboration Suite (ZCS) email servers. Zimbra Collaboration Suite is a comprehensive open-source messaging and […]

Pierluigi Paganini March 31, 2023
Russian APT group Winter Vivern targets email portals of NATO and diplomats

Russian hacking group Winter Vivern has been actively exploiting Zimbra flaws to steal the emails of NATO and diplomats. A Russian hacking group, tracked as Winter Vivern (aka TA473), has been actively exploiting vulnerabilities (CVE-2022-27926) in unpatched Zimbra instances to gain access to the emails of NATO officials, governments, military personnel, and diplomats. The CVE-2022-27926 […]

Pierluigi Paganini October 16, 2022
Threat actors hacked hundreds of servers by exploiting Zimbra CVE-2022-41352 bug

Threat actors have compromised hundreds of servers exploiting critical flaw CVE-2022-41352 in Zimbra Collaboration Suite (ZCS). Last week, researchers from Rapid7 warned of the exploitation of unpatched zero-day remote code execution vulnerability, tracked as CVE-2022-41352, in the Zimbra Collaboration Suite. Rapid7 has published technical details, including a proof-of-concept (PoC) code and indicators of compromise (IoCs) regarding […]

Pierluigi Paganini August 12, 2022
Experts warn of mass exploitation of an RCE flaw in Zimbra Collaboration Suite

Threat actors are exploiting an authentication bypass Zimbra flaw, tracked as CVE-2022-27925, to hack Zimbra Collaboration Suite email servers worldwide. An authentication bypass affecting Zimbra Collaboration Suite, tracked as CVE-2022-27925, is actively exploited to hack ZCS email servers worldwide. Zimbra is an email and collaboration platform used by more than 200,000 businesses from over 140 countries. Yesterday, August 11, CISA has […]

Pierluigi Paganini August 05, 2022
CISA adds Zimbra email bug to Known Exploited Vulnerabilities Catalog

US Critical Infrastructure Security Agency (CISA) adds a recently disclosed flaw in the Zimbra email suite to its Known Exploited Vulnerabilities Catalog. The Cybersecurity & Infrastructure Security Agency (CISA) has added a recently disclosed flaw in the Zimbra email suite, tracked as CVE-2022-27924, to its Known Exploited Vulnerabilities Catalog. In middle June, researchers from Sonarsource discovered […]

Pierluigi Paganini June 29, 2022
Path Traversal flaw in UnRAR utility can allow hacking Zimbra Mail servers

Researchers discovered a new flaw in RARlab’s UnRAR utility, tracked CVE-2022-30333, that can allow to remotely hack Zimbra Webmail servers. SonarSource researchers have discovered a new vulnerability in RARlab’s UnRAR utility, tracked as CVE-2022-30333, that can be exploited by remote attackers to execute arbitrary code on a system that relies on the binary, like Zimbra […]