Directory traversal vulnerability in pure-FTPd 1.0.22 and possibly other versions, when running on SUSE Linux Enterprise Server and possibly

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• pureftpd pure-ftpdup to 1.0.22 inclusive
• pureftpd pure-ftpd0.90
• pureftpd pure-ftpd0.91
• pureftpd pure-ftpd0.92
• pureftpd pure-ftpd0.93
• pureftpd pure-ftpd0.94
• pureftpd pure-ftpd0.95
• pureftpd pure-ftpd0.95.1
• pureftpd pure-ftpd0.95.2
• pureftpd pure-ftpd0.96
• pureftpd pure-ftpd0.96.1
• pureftpd pure-ftpd0.97
• pureftpd pure-ftpd0.97-final
• pureftpd pure-ftpd0.97.1
• pureftpd pure-ftpd0.97.2
• pureftpd pure-ftpd0.97.3
• pureftpd pure-ftpd0.97.4
• pureftpd pure-ftpd0.97.5
• pureftpd pure-ftpd0.97.6
• pureftpd pure-ftpd0.97.7

Other highest-scoring records for the same primary product.

• CVE-2020-8018User owned /etc in SLES15-SP1-CHOST-BYOS
  31Monitor
• CVE-2016-1602A code injection in the supportconfig data collection tool in supportutils in SUSE Linux Enterprise Server 12 and 12-SP1 and SUSE Linux Ente
  31Monitor
• CVE-2020-8016race condition in the packaging of texlive-filesysten
  28Monitor
• CVE-2020-8017race condition on texlive-filesystem cron job allows for the deletion of unintended files
  25Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1const file = path.join(ROOT, req.query.name);2res.sendFile(file);

1const file = path.resolve(ROOT, req.query.name);2if (!file.startsWith(ROOT + path.sep)) {3  return res.sendStatus(400);4}5res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.