# CVE-2021-20109: Memory corruption in Manage Engine Asset Explorer Agent

> A heap overflow in the Asset Explorer Agent allows remote attackers to execute arbitrary code or cause denial of service via a large POST payload.

- **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:** 19 Jul 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-3683-2c96-6v5c, UBUNTU-CVE-2021-20109

## What is CVE-2021-20109?

CVE-2021-20109 is a high-severity memory corruption vulnerability in Manage Engine Asset Explorer Agent, published on 19 Jul 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Due to the Asset Explorer agent not validating HTTPS certificates, an attacker on the network can statically configure their IP address to match the Asset Explorer's Server IP address. This will allow an attacker to send a NEWSCAN request to a listening agent on the network as well as receive the agent's HTTP request verifying its authtoken. In AEAgent.cpp, the agent responding back over HTTP is vulnerable to a Heap Overflow if the POST payload response is too large. The POST payload response is converted to Unicode using vswprintf. This is written to a buffer only 0x2000 bytes big. If POST payload is larger, then heap overflow will occur.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-20109?

It affects 1 product.


Products: Zohocorp Manageengine Assetexplorer.

## How do I fix CVE-2021-20109?

No fix has been published for CVE-2021-20109 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20109 being exploited?

There is no known exploitation of CVE-2021-20109 in the wild and no public exploit code.

## Other vulnerabilities in Manage Engine Asset Explorer Agent

- [CVE-2021-20110](https://insights.sbomify.com/CVE-2021-20110/): Integer overflow in Manage Engine Asset Explorer Agent (critical 9.8)
- [CVE-2019-12994](https://insights.sbomify.com/CVE-2019-12994/): Server-side request forgery in n/a (critical 9.1)
- [CVE-2019-12959](https://insights.sbomify.com/CVE-2019-12959/): Server-side request forgery in n/a (high 8.8)
- [CVE-2019-14693](https://insights.sbomify.com/CVE-2019-14693/): XML external entity in n/a (high 8.5)
- [CVE-2023-26601](https://insights.sbomify.com/CVE-2023-26601/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20109 and fix it if it is affected.

What it is: CVE-2021-20109 is a high-severity memory corruption vulnerability in Manage Engine Asset Explorer Agent, published on 19 Jul 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-2021-20109 in the wild and no public exploit code.

Affected product: Manage Engine Asset Explorer Agent. 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-2021-20109/ (Markdown: https://insights.sbomify.com/CVE-2021-20109/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20109
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20109
- OSV: https://osv.dev/vulnerability/CVE-2021-20109

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20109/
Summaries are generated and may contain mistakes; the official description above is the record.