Microsoft catches hackers exploiting Zimbra bug before disclosure

Microsoft’s report shows attackers were exploiting a Zimbra command-injection flaw weeks before public disclosure, using it to gain initial access, deploy web shells, steal credentials, and move laterally across mail environments. For CIOs and technology leaders, the key implication is that internet-facing collaboration and email platforms remain high-value entry points, and exposure can quickly turn into credential theft, mailbox compromise, and broader domain risk if patching and hardening lag behind threat activity.