- Issue #16040: CVE-2013-1752: nntplib: Limit maximum line lengths to 2048 to
prevent readline() calls from consuming too much memory. Patch by Jyrki
Pulliainen.
diff --git a/Lib/nntplib.py b/Lib/nntplib.py
index f519b06..f5e0d29 100644
--- a/Lib/nntplib.py
+++ b/Lib/nntplib.py
@@ -37,6 +37,13 @@
"error_reply","error_temp","error_perm","error_proto",
"error_data",]
+# maximal line length when calling readline(). This is to prevent
+# reading arbitrary lenght lines. RFC 3977 limits NNTP line length to
+# 512 characters, including CRLF. We have selected 2048 just to be on
+# the safe side.
+_MAXLINE = 2048
+
+
# Exceptions raised when an error or invalid response is received
class NNTPError(Exception):
"""Base class for all nntplib exceptions"""
@@ -200,7 +207,9 @@
def getline(self):
"""Internal: return one line from the server, stripping CRLF.
Raise EOFError if the connection is closed."""
- line = self.file.readline()
+ line = self.file.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise NNTPDataError('line too long')
if self.debugging > 1:
print '*get*', repr(line)
if not line: raise EOFError