An issue was discovered in Acronis True Image 2020 24.5.22510. anti_ransomware_service.exe keeps a log in a folder where unprivileged users have write permissions. The logs are generated in a predictable pattern, allowing an unprivileged user to create a hardlink from a (not yet created) log file to anti_ransomware_service.exe. On reboot, this forces the anti_ransomware_service to try to write its log into its own process, crashing in a SHARING VIOLATION. This crash occurs on every reboot.

An issue was discovered in Acronis True Image 2020 24.5.22510. anti_ransomware_service.exe includes functionality to quarantine files by copying a suspected ransomware file from one directory to another using SYSTEM privileges. Because unprivileged users have write permissions in the quarantine folder, it is possible to control this privileged write with a hardlink. This means that an unprivileged user can write/overwrite arbitrary files in arbitrary folders. Escalating privileges to SYSTEM is trivial with arbitrary writes. While the quarantine feature is not enabled by default, it can be forced to copy the file to the quarantine by communicating with anti_ransomware_service.exe through its REST API.

An issue was discovered in Acronis True Image 2020 24.5.22510. anti_ransomware_service.exe exposes a REST API that can be used by everyone, even unprivileged users. This API is used to communicate from the GUI to anti_ransomware_service.exe. This can be exploited to add an arbitrary malicious executable to the whitelist, or even exclude an entire drive from being monitored by anti_ransomware_service.exe.

An issue was discovered in Acronis Cyber Protect before 15 Update 1 build 26172. There is cross-site scripting (XSS) in the console.

An issue was discovered in Acronis Cyber Protect before 15 Update 1 build 26172. Because the local notification service misconfigures CORS, information disclosure can occur.

Acronis True Image for Windows prior to 2021 Update 3 allowed local privilege escalation due to a DLL hijacking vulnerability in multiple components, aka an Untrusted Search Path issue.

Acronis True Image 2021 includes an OpenSSL component that specifies an OPENSSLDIR variable as a subdirectory within C:\jenkins_agent\. Acronis True Image contains a privileged service that uses this OpenSSL component. Because unprivileged Windows users can create subdirectories off of the system root, a user can create the appropriate path to a specially-crafted openssl.cnf file to achieve arbitrary code execution with SYSTEM privileges.

Acronis True Image 2021 fails to properly set ACLs of the C:\ProgramData\Acronis directory. Because some privileged processes are executed from the C:\ProgramData\Acronis, an unprivileged user can achieve arbitrary code execution with SYSTEM privileges by placing a DLL in one of several paths within C:\ProgramData\Acronis.

Acronis Cyber Backup 12.5 and Cyber Protect 15 include an OpenSSL component that specifies an OPENSSLDIR variable as a subdirectory within C:\jenkins_agent\. Acronis Cyber Backup and Cyber Protect contain a privileged service that uses this OpenSSL component. Because unprivileged Windows users can create subdirectories off of the system root, a user can create the appropriate path to a specially-crafted openssl.cnf file to achieve arbitrary code execution with SYSTEM privileges.

An issue was discovered in Acronis Cyber Backup before 12.5 Build 16342. Some API endpoints on port 9877 under /api/ams/ accept an additional custom Shard header. The value of this header is afterwards used in a separate web request issued by the application itself. This can be abused to conduct SSRF attacks against otherwise unreachable Acronis services that are bound to localhost such as the NotificationService on 127.0.0.1:30572.