# CVE-2017-6542: Memory corruption in n/a

> Remote attackers can trigger a buffer overflow in PuTTY via large agent protocol messages, potentially leading to code execution or denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 27 Mar 2017
- **Updated:** 5 Aug 2024
- **Also known as:** ALPINE-CVE-2017-6542, DEBIAN-CVE-2017-6542, GHSA-6q3h-v425-7xx2, MGASA-2017-0093, UBUNTU-CVE-2017-6542

## What is CVE-2017-6542?

CVE-2017-6542 is a critical memory corruption vulnerability in Opensuse Leap, published on 27 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ssh_agent_channel_data function in PuTTY before 0.68 allows remote attackers to have unspecified impact via a large length value in an agent protocol message and leveraging the ability to connect to the Unix-domain socket representing the forwarded agent connection, which trigger a buffer overflow.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2017-6542?

It affects 3 products.


Products: Opensuse Leap, Opensuse Project Leap, Putty Putty.

## How do I fix CVE-2017-6542?

Upgrade to a fixed version.

## Is CVE-2017-6542 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-6542 exists.

Public exploit code:

- PuTTY < 0.68 - 'ssh_agent_channel_data' Integer Overflow Heap Corruption (exploitdb)

## Other vulnerabilities in Opensuse Leap

- [CVE-2015-4902](https://insights.sbomify.com/CVE-2015-4902/): Oracle Java SE Integrity Check (medium 5.3, exploited in the wild)
- [CVE-2017-14804](https://insights.sbomify.com/CVE-2017-14804/): package builds could use directory traversal to write outside of target area (critical 9.9)
- [CVE-2019-20787](https://insights.sbomify.com/CVE-2019-20787/): Teeworlds before 0.7.4 has an integer overflow when computing a tilemap size. (critical 9.8)
- [CVE-2019-8341](https://insights.sbomify.com/CVE-2019-8341/): Code injection in n/a (critical 9.8)
- [CVE-2019-6438](https://insights.sbomify.com/CVE-2019-6438/): Other in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-6542 and fix it if it is affected.

What it is: CVE-2017-6542 is a critical memory corruption vulnerability in Opensuse Leap, published on 27 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-6542 exists.

Affected product: Opensuse Leap. 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-2017-6542/ (Markdown: https://insights.sbomify.com/CVE-2017-6542/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-6542
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-6542
- OSV: https://osv.dev/vulnerability/CVE-2017-6542

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-6542/
Summaries are generated and may contain mistakes; the official description above is the record.