# CVE-2020-9451: Denial of service in n/a

> An unprivileged user can cause a persistent denial of service in Acronis True Image by creating hardlinks to log files, crashing the anti-ransomware service on reboot.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 May 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-wghq-w68q-jx98

## What is CVE-2020-9451?

CVE-2020-9451 is a medium-severity denial of service vulnerability in n/a, published on 25 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-276 (Incorrect Default Permissions)

## Which versions are affected by CVE-2020-9451?

It affects 1 product.


Products: Acronis True Image 2020.

## How do I fix CVE-2020-9451?

No fix has been published for CVE-2020-9451 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-9451 being exploited?

There is no known exploitation of CVE-2020-9451 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-9450](https://insights.sbomify.com/CVE-2020-9450/): Missing authorization in n/a (high 7.8)
- [CVE-2020-9452](https://insights.sbomify.com/CVE-2020-9452/): Privilege escalation in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-9451 and fix it if it is affected.

What it is: CVE-2020-9451 is a medium-severity denial of service vulnerability in n/a, published on 25 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-9451 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-9451/ (Markdown: https://insights.sbomify.com/CVE-2020-9451/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-9451
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-9451
- OSV: https://osv.dev/vulnerability/CVE-2020-9451

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-9451/
Summaries are generated and may contain mistakes; the official description above is the record.