# CVE-2020-27795: Null dereference in radare2

> A null pointer dereference in radare2's adf command causes a segmentation fault, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 19 Aug 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r23c-h6ff-98mj, UBUNTU-CVE-2020-27795

## What is CVE-2020-27795?

CVE-2020-27795 is a high-severity vulnerability in Radare Radare2, published on 19 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A segmentation fault was discovered in radare2 with adf command. In libr/core/cmd_anal.c, when command "adf" has no or wrong argument, anal_fcn_data (core, input + 1) --> RAnalFunction *fcn = r_anal_get_fcn_in (core->anal, core->offset, -1); returns null pointer for fcn causing segmentation fault later in ensure_fcn_range (fcn).

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2020-27795?

It affects 1 product.


Products: Radare Radare2.

## How do I fix CVE-2020-27795?

No fix has been published for CVE-2020-27795 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27795 being exploited?

There is no known exploitation of CVE-2020-27795 in the wild and no public exploit code.

## Other vulnerabilities in Radare Radare2

- [CVE-2025-1864](https://insights.sbomify.com/CVE-2025-1864/): Buffer Overflow and Potential Code Execution in Radare2 (critical 10.0)
- [CVE-2025-1744](https://insights.sbomify.com/CVE-2025-1744/): Out-of-bounds Write in radare2 (critical 10.0)
- [CVE-2021-32494](https://insights.sbomify.com/CVE-2021-32494/): Denial of service in radare2 (critical 10.0)
- [CVE-2021-32495](https://insights.sbomify.com/CVE-2021-32495/): Use after free in radare2 (critical 10.0)
- [CVE-2024-29646](https://insights.sbomify.com/CVE-2024-29646/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27795 and fix it if it is affected.

What it is: CVE-2020-27795 is a high-severity vulnerability in Radare Radare2, published on 19 Aug 2022. 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-2020-27795 in the wild and no public exploit code.

Affected product: Radare Radare2. 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-2020-27795/ (Markdown: https://insights.sbomify.com/CVE-2020-27795/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27795
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27795
- OSV: https://osv.dev/vulnerability/CVE-2020-27795

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-27795/
Summaries are generated and may contain mistakes; the official description above is the record.