# CVE-2020-27540: Command injection in n/a

> Attackers can execute arbitrary commands on Rostelecom IP cameras by inserting a malicious SD card, bypassing firmware signature verification.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-qmf6-mw8h-6m87

## What is CVE-2020-27540?

CVE-2020-27540 is a critical command injection vulnerability in n/a, published on 25 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Bash injection vulnerability and bypass of signature verification in Rostelecom CS-C2SHW 5.0.082.1. The camera reads firmware update configuration from SD card file vc\version.json. fw-sign parameter and from this configuration is directly inserted into a bash command. Firmware update is run automatically if there is special file on the inserted SD card.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2020-27540?

It affects 1 product.


Products: Company Cs-C2shw Firmware.

## How do I fix CVE-2020-27540?

No fix has been published for CVE-2020-27540 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27540 being exploited?

There is no known exploitation of CVE-2020-27540 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-27539](https://insights.sbomify.com/CVE-2020-27539/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-27541](https://insights.sbomify.com/CVE-2020-27541/): Integer overflow in n/a (high 7.5)
- [CVE-2020-27542](https://insights.sbomify.com/CVE-2020-27542/): Command injection in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27540 and fix it if it is affected.

What it is: CVE-2020-27540 is a critical command injection vulnerability in n/a, published on 25 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-27540 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-2020-27540/ (Markdown: https://insights.sbomify.com/CVE-2020-27540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27540
- OSV: https://osv.dev/vulnerability/CVE-2020-27540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27540/
Summaries are generated and may contain mistakes; the official description above is the record.