CVE-2019-5544 VMware VMware ESXi and Horizon DaaS: memory-safety flaw
In plain words: The program mishandles the memory it uses to keep track of data. A specially made input can scramble that memory. Usually lets an attacker crash the program or run their own code with its permissions.
Confirmed exploited by CISA on · US federal patch deadline May 3, 2022
What to do
- Install VMware's security update for VMware ESXi and Horizon DaaS. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Vulnerability
- Product
- VMware VMware ESXi and Horizon DaaS
- CISA description
- VMware ESXi and Horizon Desktop as a Service (DaaS) OpenSLP contains a heap-based buffer overflow vulnerability that allows an attacker with network access to port 427 to overwrite the heap of the OpenSLP service to perform remote code execution.
- Type of flaw
- Memory-safety flaw (CWE-787)
- Confirmed exploited
- Nov 3, 2021 — known to be used in ransomware attacks
- US federal patch deadline
- May 3, 2022
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Answering about CVE-2019-5544 ·
Questions about CVE-2019-5544
Is CVE-2019-5544 being exploited?
Yes. CISA added CVE-2019-5544 to its Known Exploited Vulnerabilities catalog on Nov 3, 2021, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2019-5544?
Install VMware's security update for VMware ESXi and Horizon DaaS. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2019-5544?
Only if you use VMware VMware ESXi and Horizon DaaS. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.