12,194guides5,442members
8 Octporterneuman.mx: PowerShell and JavaScript files tied to the AveMaria remote access trojan, and what to do8 Octdonutclientsmods.xyz: fake DonutSMP Minecraft mods tagged SilentNet, and what to do if you ran one8 Octsqpengg.com: a server handing out crypted PowerShell scripts, and what to do if one ran on your PC8 Octdonutsmpcheats.org: fake Minecraft cheat mods with the SilentNet stealer, and what to do if you installed one8 Octmaciejbi.hosting24.pl: a hosting subdomain that served Remcos scripts and a stego picture, and what to do if your PC fetched them8 Oct87130921-60-20220830152356.webstarterz.com: an open folder serving Formbook and XWorm PowerShell scripts, and what to do if one ran8 Octficus.in: picture files hiding the Remcos remote access trojan, and what to do if a script fetched them8 OctOpenDrive virus: why web.opendrive.com shows up in malware alerts, and what to do if a file from it installed Remcos

Actively exploited vulnerability

Synacor Zimbra Collaboration Suite (ZCS): cross-site scripting flaw under attack

CVE-2023-37580 · Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability

Business software6.1 medium

What is affected

Synacor Zimbra Collaboration Suite (ZCS) is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

Synacor Zimbra Collaboration Suite (ZCS) contains a cross-site scripting vulnerability impacting the confidentiality and integrity of data.

CISA's description

What an attacker can do

This is a cross-site scripting flaw. It lets an attacker plant a script that runs in the browser of anyone who opens the affected page, which lets them steal that person's session or act on their behalf.

How it is reached
Over the internet or network
Access the attacker needs
No account needed
Does the victim have to do something?
Yes, the victim must open or click something

What to do

  1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
  2. If you administer Synacor Zimbra Collaboration Suite (ZCS) at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
  3. If the product is past its support date and no fix exists, take it off the internet or retire it.

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Action required by CISA for US federal agencies

Vendor advisories and fixes

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on July 27, 2023, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by August 17, 2023, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 49% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 99% of all scored vulnerabilities.

Its CVSS severity score is 6.1 out of 10 (medium), as recorded in the US National Vulnerability Database.

Technical description

Zimbra Collaboration (ZCS) 8 before 8.8.15 Patch 41 allows XSS in the Zimbra Classic Web Client.

NIST National Vulnerability Database
5,442 members already hereReading, writing, commenting and voting. 0 verified · 167 joined this year
All membersJoin