Issue #16038: CVE-2013-1752: ftplib: Limit amount of data read by

limiting the call to readline().  Original patch by Michał
Jastrzębski and Giampaolo Rodola.

1 files changed, 12 insertions, 3 deletions

diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index fcd4b14..9538fec 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -50,6 +50,8 @@ MSG_OOB = 0x1                           # Process data out of band
 
 # The standard FTP server control port
 FTP_PORT = 21
+# The sizehint parameter passed to readline() calls
+MAXLINE = 8192
 
 
 # Exception raised when an error or invalid response is received
@@ -97,6 +99,7 @@ class FTP:
     debugging = 0
     host = ''
     port = FTP_PORT
+    maxline = MAXLINE
     sock = None
     file = None
     welcome = None
@@ -197,7 +200,9 @@ class FTP:
     # Internal: return one line from the server, stripping CRLF.
     # Raise EOFError if the connection is closed
     def getline(self):
-        line = self.file.readline()
+        line = self.file.readline(self.maxline + 1)
+        if len(line) > self.maxline:
+            raise Error("got more than %d bytes" % self.maxline)
         if self.debugging > 1:
             print('*get*', self.sanitize(line))
         if not line:
@@ -463,7 +468,9 @@ class FTP:
         with self.transfercmd(cmd) as conn, \
                  conn.makefile('r', encoding=self.encoding) as fp:
             while 1:
-                line = fp.readline()
+                line = fp.readline(self.maxline + 1)
+                if len(line) > self.maxline:
+                    raise Error("got more than %d bytes" % self.maxline)
                 if self.debugging > 2:
                     print('*retr*', repr(line))
                 if not line:
@@ -522,7 +529,9 @@ class FTP:
         self.voidcmd('TYPE A')
         with self.transfercmd(cmd) as conn:
             while 1:
-                buf = fp.readline()
+                buf = fp.readline(self.maxline + 1)
+                if len(buf) > self.maxline:
+                    raise Error("got more than %d bytes" % self.maxline)
                 if not buf:
                     break
                 if buf[-2:] != B_CRLF: