Inefficient regular expression complexity in basic-ftp - #VU164367

Vulnerability details

The vulnerability allows a remote attacker to cause a temporary denial of service by blocking a basic-ftp client's Node.js event loop.

The vulnerability exists due to quadratic-time regular-expression backtracking in MLSD listing detection and PASV response parsing when processing crafted FTP server responses. A remote attacker can operate or compromise an FTP server and return a listing line of repeated '=' characters without ';', or refuse EPSV and return a PASV '227 ' response containing a long comma-free digit sequence, to stall all work sharing the client's event loop.

Affected software

Remediation

External References

• https://github.com/patrickjuchli/basic-ftp/security/advisories/GHSA-5rfr-xx34-2xxv

Related Security Bulletins

• Inefficient regular expression complexity in basic-ftp