FTP PASV SSRF, ftpcp() does not use actual peer address, trusts server-supplied PASV host address
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.9epss 0.5%
exploitation probability
0.5%top 63% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
Python Software Foundation · CPythonReferences
https://github.com/python/cpython/commit/2bbcf3fb7a420a05605576c0f9468d4675381b5fhttps://github.com/python/cpython/commit/5dadc64673ce875ebfb24163907777dae0f6ca06https://github.com/python/cpython/commit/7d95a1dc7382b55cba7fdd6a110336077584a4f0https://github.com/python/cpython/commit/bb3446dda6c49b32e67c11dbbbf221b40be00763https://github.com/python/cpython/commit/c88704431ea3248ca769384c13856330976fac1dhttps://github.com/python/cpython/commit/eac4fe3b2c77693790a5ef7dfab127c1fee81bf9https://github.com/python/cpython/commit/ef12d0dc824baccf737bba1458e5eed3d1e0fcebhttps://github.com/python/cpython/issues/87451https://github.com/python/cpython/pull/149648https://mail.python.org/archives/list/security-announce@python.org/thread/ITF2BAPBQEPYK3LDMPRSY435JGNHYNDP/