# CVE-2020-21503: Business logic in n/a

> Attackers can manipulate credit parameters to purchase products for free by bypassing price validation logic.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-42wv-rq8p-rm59

## What is CVE-2020-21503?

CVE-2020-21503 is a high-severity vulnerability in n/a, published on 5 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

waimai Super Cms 20150505 has a logic flaw allowing attackers to modify a price, before form submission, by observing data in a packet capture. By setting the index.php?m=gift&a=addsave credit parameter to -1, the product is sold for free.

Weakness: CWE-668 (Exposure of Resource to Wrong Sphere)

## Which versions are affected by CVE-2020-21503?

It affects 1 product.


Products: Waimai Super Cms Project Waimai Super Cms.

## How do I fix CVE-2020-21503?

No fix has been published for CVE-2020-21503 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-21503 being exploited?

There is no known exploitation of CVE-2020-21503 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-21504](https://insights.sbomify.com/CVE-2020-21504/): Cross-site scripting in n/a (medium 6.1)
- [CVE-2020-21505](https://insights.sbomify.com/CVE-2020-21505/): Cross-site scripting in n/a (medium 6.1)
- [CVE-2020-21506](https://insights.sbomify.com/CVE-2020-21506/): Cross-site scripting in n/a (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-21503 and fix it if it is affected.

What it is: CVE-2020-21503 is a high-severity vulnerability in n/a, published on 5 Oct 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-2020-21503 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-2020-21503/ (Markdown: https://insights.sbomify.com/CVE-2020-21503/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-21503
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-21503
- OSV: https://osv.dev/vulnerability/CVE-2020-21503

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-21503/
Summaries are generated and may contain mistakes; the official description above is the record.