# CVE-2020-24034: Deserialization in n/a

> Authenticated users can exploit insecure deserialization in session cookies to escalate privileges to internal accounts and flash custom firmware.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Sep 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-qh8j-94w4-68q5

## What is CVE-2020-24034?

CVE-2020-24034 is a high-severity unsafe deserialization vulnerability in n/a, published on 1 Sep 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Sagemcom F@ST 5280 routers using firmware version 1.150.61 have insecure deserialization that allows any authenticated user to perform a privilege escalation to any other user. By making a request with valid sess_id, nonce, and ha1 values inside of the serialized session cookie, an attacker may alter the user value inside of this cookie, and assume the role and permissions of the user specified. By assuming the role of the user internal, which is inaccessible to end users by default, the attacker gains the permissions of the internal account, which includes the ability to flash custom firmware to the router, allowing the attacker to achieve a complete compromise.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2020-24034?

It affects 1 product.


Products: Sagemcom F\@st 5280 Router Firmware.

## How do I fix CVE-2020-24034?

No fix has been published for CVE-2020-24034 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-24034 being exploited?

There is no known exploitation of CVE-2020-24034 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-24034 and fix it if it is affected.

What it is: CVE-2020-24034 is a high-severity unsafe deserialization vulnerability in n/a, published on 1 Sep 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-24034 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-2020-24034/ (Markdown: https://insights.sbomify.com/CVE-2020-24034/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-24034
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-24034
- OSV: https://osv.dev/vulnerability/CVE-2020-24034

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-24034/
Summaries are generated and may contain mistakes; the official description above is the record.