CVE-2007-4321 Denial of service in n/a
Remote attackers can cause denial of service by injecting IP addresses into SSH logs, which fail2ban incorrectly parses into the hosts.deny file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2007-4321?
CVE-2007-4321 is a medium-severity denial of service vulnerability in n/a, published on 14 Aug 2007. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
fail2ban 0.8 and earlier does not properly parse sshd log files, which allows remote attackers to add arbitrary hosts to the /etc/hosts.deny file and cause a denial of service by adding arbitrary IP addresses to the sshd log file, as demonstrated by logging in via ssh with a client protocol version identification containing an IP address string, a different vector than CVE-2006-6302.
Which versions are affected by CVE-2007-4321?
It affects 1 product.
Products include Fail2ban Fail2ban.
How do I fix CVE-2007-4321?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2007-4321 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2007-4321 exists.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2007-4321, DSA-1456-1, GHSA-5jfx-9p58-q8pj.