CVE-2026-8328FTP PASV SSRF, ftpcp() does not use actual peer address, trusts server-supplied PASV host address

Description

The ftpcp() function in Lib/ftplib.py was not updated when CVE-2021-4189 was fixed. While makepasv() was patched to replace server-supplied PASV host addresses with the actual peer address (getpeername()[0]), ftpcp() still calls parse227() directly and passes the raw attacker-controllable IP address and port to target.sendport(). This patch is related to CVE-2021-4189.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/python/cpython/issues/87451 issue-tracking
• https://github.com/python/cpython/pull/149648 patch
• https://mail.python.org/archives/list/security-announce@python.org/thread/ITF2BAPBQEPYK3LDMPRSY435JGNHYNDP/ vendor-advisory
• https://github.com/python/cpython/commit/5dadc64673ce875ebfb24163907777dae0f6ca06 patch
• https://github.com/python/cpython/commit/7d95a1dc7382b55cba7fdd6a110336077584a4f0 patch
• https://github.com/python/cpython/commit/bb3446dda6c49b32e67c11dbbbf221b40be00763 patch
• https://github.com/python/cpython/commit/c88704431ea3248ca769384c13856330976fac1d patch
• https://github.com/python/cpython/commit/eac4fe3b2c77693790a5ef7dfab127c1fee81bf9 patch
• https://github.com/python/cpython/commit/2bbcf3fb7a420a05605576c0f9468d4675381b5f patch
• https://github.com/python/cpython/commit/ef12d0dc824baccf737bba1458e5eed3d1e0fceb patch
• https://cert-portal.siemens.com/productcert/html/ssa-457936.html