CVE-2017-7418: Medium severity ProFTPD ProFTPD vulnerability
ProFTPD before 1.3.5e and 1.3.6 before 1.3.6rc5 controls whether the home directory of a user could contain a symbolic link through the AllowChrootSymlinks configuration option, but checks only the last path component when enforcing AllowChrootSymlinks. Attackers with local access could bypass the AllowChrootSymlinks control by replacing a path component (other than the last one) with a symbolic link. The threat model includes an attacker who is not granted full filesystem access by a hosting provider, but can reconfigure the home directory of an FTP user.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ProFTPDto a version that resolves this vulnerability.Fixed in 1.3.5e - Upgrade
Upgrade
ProFTPDto a version that resolves this vulnerability.Fixed in 1.3.6rc5 - Configuration
Ensure AllowChrootSymlinks enforcement in ProFTPD checks all path components (not only the last component) when validating chroot/home directory paths, so an attacker cannot bypass by replacing a non-last path component with a symbolic link.
ProFTPD AllowChrootSymlinks = enforce correct behavior for symlinks in non-last path components
Event History
Frequently Asked Questions
What is the severity of CVE-2017-7418?
CVE-2017-7418 has a medium severity rating as it allows local attackers to bypass security measures.
How do I fix CVE-2017-7418?
To fix CVE-2017-7418, upgrade to ProFTPD 1.3.5e or 1.3.6rc5 or later versions.
Who is affected by CVE-2017-7418?
CVE-2017-7418 affects users of ProFTPD versions prior to 1.3.5e and those using 1.3.6 before 1.3.6rc5.
What types of attacks are possible with CVE-2017-7418?
Attackers with local access can create symbolic links in user home directories allowing unauthorized access.
Can remote attackers exploit CVE-2017-7418?
No, CVE-2017-7418 requires local access to exploit the vulnerability.