https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Thu, 08 Oct 2026 00:57:11 +0000 https://vulnerability.circl.lu/vuln/ubuntu-cve-2021-32749 <p><strong>Affected:</strong> Ubuntu:Pro:14.04:LTS: fail2ban, Ubuntu:Pro:16.04:LTS: fail2ban, Ubuntu:Pro:18.04:LTS: fail2ban, Ubuntu:Pro:20.04:LTS: fail2ban</p> <p>fail2ban is a daemon to ban hosts that cause multiple authentication errors. In versions 0.9.7 and prior, 0.10.0 through 0.10.6, and 0.11.0 through 0.11.2, there is a vulnerability that leads to possible remote code execution in the mailing action mail-whois. Command `mail` from mailutils package used in mail actions like `mail-whois` can execute command if unescaped sequences (`\n~`) are available in &#34;foreign&#34; input (for instance in whois output). To exploit the vulnerability, an attacker would need to insert malicious characters into the response sent by the whois server, either via a MITM attack or by taking over a whois server. The issue is patched in versions 0.10.7 and 0.11.3. As a workaround, one may avoid the usage of action `mail-whois` or patch the vulnerability manually.</p> <p><strong>Affected:</strong> Ubuntu:Pro:14.04:LTS: fail2ban, Ubuntu:Pro:16.04:LTS: fail2ban, Ubuntu:Pro:18.04:LTS: fail2ban, Ubuntu:Pro:20.04:LTS: fail2ban</p> <p>fail2ban is a daemon to ban hosts that cause multiple authentication errors. In versions 0.9.7 and prior, 0.10.0 through 0.10.6, and 0.11.0 through 0.11.2, there is a vulnerability that leads to possible remote code execution in the mailing action mail-whois. Command `mail` from mailutils package used in mail actions like `mail-whois` can execute command if unescaped sequences (`\n~`) are available in &#34;foreign&#34; input (for instance in whois output). To exploit the vulnerability, an attacker would need to insert malicious characters into the response sent by the whois server, either via a MITM attack or by taking over a whois server. The issue is patched in versions 0.10.7 and 0.11.3. As a workaround, one may avoid the usage of action `mail-whois` or patch the vulnerability manually.</p> https://vulnerability.circl.lu/vuln/ubuntu-cve-2021-32749