Fedora 28 update for openssh
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2018-15473 |
| CWE-ID | CWE-388 |
| Exploitation vector | Network |
| Public exploit | Public exploit code for vulnerability #1 is available. |
| Vulnerable software |
Fedora Operating systems & Components / Operating system openssh Operating systems & Components / Operating system package or component |
| Vendor | Fedoraproject |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
1) User enumeration
EUVDB-ID: #VU14440
Risk: Medium
CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:A/U:Green]
CVE-ID: CVE-2018-15473
CWE-ID:
CWE-388 - Error Handling
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to enumerate all accounts on the system.
The vulnerability exists due to a logical error in auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c files when processing authentication requests. A remote attacker can send a specially crafted chain of packets and monitor behavior of openssh server to determine presence of a valid username. The server will drop connection upon receiving a malformed authentication packets if the username is valid.
MitigationInstall updates from vendor's repository.
Vulnerable software versionsFedora: 28
openssh: before 7.8p1-1.fc28
CPE2.3 External linkshttps://bodhi.fedoraproject.org/updates/FEDORA-2018-065a7722ee
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.
