A vulnerability (CVE-2023-21932) was found in Oracle Opera (also known as Micros Opera) – a property management system that is widely used in large resort and hotel chains. The vulnerability can be exploited by unauthenticated remote attackers to access sensitive data.  

CVE-2023-21932 has a CVSS score of 7.2 and impacts version 5.6 of the Oracle Hospitality OPERA 5 Property Services product. Oracle stated that exploiting the vulnerability requires significant effort and privileged access to the network through HTTP. However, the researchers at Asettnote have contradicted this claim by demonstrating that attackers can effortlessly execute pre-auth commands by obtaining a JNDI connection name from specific URLs. An attacker can accomplish this by breaking the solutions encryption scheme and using it to encrypt arbitrary strings. 

“As seen above, RCE is possible without any special access or knowledge. All steps performed in the exploitation of this vulnerability were without any authentication. This vulnerability should have a CVSS score of 10.0.” – Assetnote  

Although Oracle released a patch for the vulnerability in April 2023, security researchers didn't take notice of it until this month due to the specialized nature of the software. There have been no major critical vulnerabilities in Oracle Opera since 2016. The Oracle Hospitality Opera 5 Property Services product is used by Radisson Hotels, Accor Hotels, Wyndham Group, Marriot, and IHG.  



avertium's recommendations

  • For more information on how CVE-2023-21932 can be exploited, please read Assetnote’s proof of concept blog 
  • It is recommended not to expose Oracle Opera to the internet.  
  • If you have not already done so, please follow Oracle’s patch guidance for CVE-2023-21932.  
  • CVSS (Common Vulnerability Scoring System) 
    • CVSS Base Score – 7.2  
    • Impact Subscore – 5.3 
    • Exploitability Subscore – 1.3  
    • CVSS Temporal Score – 6.5  
    • CVSS Environmental Score – 8.9 
    • Modified Impact Subscore – 5.3 
    • Overall CVSS Score – 8.9  




At this time, there are no known IoCs associated with CVE-2023-21932. Avertium’s threat hunters remain vigilant in locating IoCs for our customers. Should any be located, Avertium will disclose them as soon as possible. For more information on how Avertium can help protect your organization, please reach out to your Avertium Service Delivery Manager or Account Executive.   



How Avertium is Protecting Our CUSTOMERS

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Exploiting an Order of Operations Bug to Achieve RCE in Oracle Opera – Assetnote 

Hotels at Risk From Bug in Oracle Property Management Software (darkreading.com) 

Easily exploitable flaw in Oracle Opera could spell trouble for hotel chains (CVE-2023-21932) - Help Net Security 

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