# CVE-2023-51773: Memory corruption in n/a

> A buffer over-read in the BACnet Stack library allows attackers to cause denial of service or disclose sensitive memory contents.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:** 25 Dec 2023
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-3j77-72gm-5rj8

## What is CVE-2023-51773?

CVE-2023-51773 is a critical memory corruption vulnerability in n/a, published on 25 Dec 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

BACnet Stack before 1.3.2 has a decode function APDU buffer over-read in bacapp_decode_application_data in bacapp.c.

Weakness: CWE-126 (Buffer Over-read)

## Which versions are affected by CVE-2023-51773?

It affects 1 product.


Products: Bacnetstack Bacnet Stack.

## How do I fix CVE-2023-51773?

No fix has been published for CVE-2023-51773 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-51773 being exploited?

There is no known exploitation of CVE-2023-51773 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-41475](https://insights.sbomify.com/CVE-2026-41475/): BACnet Stack: Out-of-Bounds Read in WritePropertyMultiple Decoder via Deprecated Tag Parser (high 8.7)
- [CVE-2026-41502](https://insights.sbomify.com/CVE-2026-41502/): BACnet Stack: Off-by-One Out-of-Bounds Read in ReadPropertyMultiple Object ID Decoder (high 8.7)
- [CVE-2026-41503](https://insights.sbomify.com/CVE-2026-41503/): BACnet Stack: Out-of-Bounds Read in ReadPropertyMultiple Property Decoder via Deprecated Tag Parser (high 8.7)
- [CVE-2026-26264](https://insights.sbomify.com/CVE-2026-26264/): BACnet Stack WriteProperty decoding length underflow leads to OOB read and crash (high 7.8)
- [CVE-2026-21878](https://insights.sbomify.com/CVE-2026-21878/): BACnet Stack Improperly Limits Pathnames to a Restricted Directory (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-51773 and fix it if it is affected.

What it is: CVE-2023-51773 is a critical memory corruption vulnerability in n/a, published on 25 Dec 2023. 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-2023-51773 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-2023-51773/ (Markdown: https://insights.sbomify.com/CVE-2023-51773/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-51773
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-51773
- OSV: https://osv.dev/vulnerability/CVE-2023-51773

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-51773/
Summaries are generated and may contain mistakes; the official description above is the record.