Auth bypass in Drakkan Sftpgo
CVE-2022-36071
SFTPGo is configurable SFTP server with optional HTTP/S, FTP/S and WebDAV support. SFTPGo WebAdmin and WebClient support login using TOTP (Time-based One Time Passwords) as a secondary authentication factor. Because TOTPs are often configured on mobile devices that can be lost, stolen or damaged, SFTPGo also supports recovery codes. These are a set of one time use codes that can be used instead of the TOTP. In SFTPGo versions from version 2.2.0 to 2.3.3 recovery codes can be generated before enabling two-factor authentication. An attacker who knows the user's password could potentially generate some recovery codes and then bypass two-factor authentication after it is enabled on the account at a later time. This issue has been fixed in version 2.3.4. Recovery codes can now only be generated after enabling two-factor authentication and are deleted after disabling it.
Vulnerability class: Broken Authentication
EPSS: 0.005 (42.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L.
Affected products
- Drakkan Sftpgo — versions >= 2.2.0, < 2.3.4
- Sftpgo_project Sftpgo
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory, Mitigation)
- security-advisories@github.com (Exploit, Patch, Third Party Advisory, x_refsource_MISC, Issue Tracking)
Frequently asked questions
- What is CVE-2022-36071?
- CVE-2022-36071 is a high-severity vulnerability in Drakkan Sftpgo, classified under Improper Authentication. CVSS score: 8.3/10. Published 2022-09-02.
- How severe is CVE-2022-36071?
- High severity. CVSS v3 base score is 8.3 out of 10.