# CVE-2018-0131: Information disclosure in IOS and IOS XE

> An unauthenticated remote attacker can obtain encrypted nonces from IKEv1 sessions on Cisco IOS devices configured with RSA-encrypted nonces.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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:** 14 Aug 2018
- **Updated:** 26 Nov 2024
- **Also known as:** GHSA-q37w-h76h-2g8q

## What is CVE-2018-0131?

CVE-2018-0131 is a medium-severity vulnerability in Cisco Ios, published on 14 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the implementation of RSA-encrypted nonces in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to obtain the encrypted nonces of an Internet Key Exchange Version 1 (IKEv1) session. The vulnerability exists because the affected software responds incorrectly to decryption failures. An attacker could exploit this vulnerability sending crafted ciphertexts to a device configured with IKEv1 that uses RSA-encrypted nonces. A successful exploit could allow the attacker to obtain the encrypted nonces. Cisco Bug IDs: CSCve77140.

Weakness: CWE-326 (Inadequate Encryption Strength)

## Which versions are affected by CVE-2018-0131?

It affects 2 products.


Products: Cisco Ios, Cisco Ios Xe.

## How do I fix CVE-2018-0131?

No fix has been published for CVE-2018-0131 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-0131 being exploited?

There is no known exploitation of CVE-2018-0131 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Ios

- [CVE-2017-12240](https://insights.sbomify.com/CVE-2017-12240/): Cisco IOS and IOS XE Software DHCP Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2017-3881](https://insights.sbomify.com/CVE-2017-3881/): Cisco IOS and IOS XE Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2018-0167](https://insights.sbomify.com/CVE-2018-0167/): Cisco IOS, XR, and XE Software Buffer Overflow (high 8.8, exploited in the wild)
- [CVE-2017-6736](https://insights.sbomify.com/CVE-2017-6736/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2017-6737](https://insights.sbomify.com/CVE-2017-6737/): Cisco IOS and IOS XE Software SNMP Remote Code Execution (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-0131 and fix it if it is affected.

What it is: CVE-2018-0131 is a medium-severity vulnerability in Cisco Ios, published on 14 Aug 2018. 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-2018-0131 in the wild and no public exploit code.

Affected product: Cisco Ios. 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-2018-0131/ (Markdown: https://insights.sbomify.com/CVE-2018-0131/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-0131
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-0131
- OSV: https://osv.dev/vulnerability/CVE-2018-0131

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-0131/
Summaries are generated and may contain mistakes; the official description above is the record.