# CVE-2020-12740: Memory corruption in n/a

> A heap-based buffer over-read in Tcpreplay allows attackers to cause denial of service or disclose sensitive memory contents via crafted packets.

- **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:** Yes
- **Published:** 8 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-12740, GHSA-95wm-mm55-cxhx, MGASA-2020-0278, UBUNTU-CVE-2020-12740, openSUSE-SU-2026:12337-1

## What is CVE-2020-12740?

CVE-2020-12740 is a critical memory corruption vulnerability in Broadcom Tcpreplay, published on 8 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

tcprewrite in Tcpreplay through 4.3.2 has a heap-based buffer over-read during a get_c operation. The issue is being triggered in the function get_ipv6_next() at common/get.c.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2020-12740?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tcpreplay` | openSUSE:Tumbleweed | All versions | 4.6.2-1.1 |

Products: Broadcom Tcpreplay, Fedoraproject Fedora.

## How do I fix CVE-2020-12740?

Upgrade to a fixed version.

## Is CVE-2020-12740 being exploited?

There is no known exploitation of CVE-2020-12740 in the wild and no public exploit code.

## Other vulnerabilities in Broadcom Tcpreplay

- [CVE-2018-18408](https://insights.sbomify.com/CVE-2018-18408/): Use after free in n/a (critical 9.8)
- [CVE-2025-51006](https://insights.sbomify.com/CVE-2025-51006/): Use after free in n/a (high 7.8)
- [CVE-2022-37047](https://insights.sbomify.com/CVE-2022-37047/): Memory corruption in n/a (high 7.8)
- [CVE-2022-37048](https://insights.sbomify.com/CVE-2022-37048/): Memory corruption in n/a (high 7.8)
- [CVE-2022-37049](https://insights.sbomify.com/CVE-2022-37049/): Memory corruption in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-12740 and fix it if it is affected.

What it is: CVE-2020-12740 is a critical memory corruption vulnerability in Broadcom Tcpreplay, published on 8 May 2020. 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-2020-12740 in the wild and no public exploit code.

Affected product: Broadcom Tcpreplay. 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-2020-12740/ (Markdown: https://insights.sbomify.com/CVE-2020-12740/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-12740
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-12740
- OSV: https://osv.dev/vulnerability/CVE-2020-12740

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-12740/
Summaries are generated and may contain mistakes; the official description above is the record.