Description of problem:
When using SimpleXMLRPCServer from the standard library, if a client connection is closed before the complete request body has been received the server will enter an infinite loop consuming memory.
Version-Release number of selected component (if applicable):
python-2.6.6-29.el6.x8664
How reproducible:
always
Steps to Reproduce:
1. Start the server: >> import SimpleXMLRPCServer, SocketServer >> class Server(SocketServer.ThreadingMixIn, SimpleXMLRPCServer.SimpleXMLRPCServer): pass ... >> Server(('0.0.0.0', 12345)).serveforever()
2. Simulate a malicious or flakey client: $ echo -e 'POST /RPC2 HTTP/1.0\r\nContent-Length: 100\r\n\r\nlol bye' | nc localhost 12345 ^C
Actual results:
Server goes nuts, with a thread stuck in an infinite loop eating memory.
Expected results:
Bad request is discarded.
Additional info:
The bug is in /usr/lib64/python2.6/SimpleXMLRPCServer.py at line 453:
# Get arguments by reading body of request. # We read this in chunks to avoid straining # socket.read(); around the 10 or 15Mb mark, some platforms # begin to have problems (bug #792570). maxchunksize = 1010241024 sizeremaining = int(self.headers["content-length"]) L = [] while sizeremaining: chunksize = min(sizeremaining, maxchunksize) L.append(self.rfile.read(chunksize)) sizeremaining -= len(L[-1]) data = ''.join(L)
This code does not correctly handle EOF from self.rfile.read().
A security flaw was found in the way handlers for ftp:// and file:// URL schemes in the Python urllib and urllib2 extensible libraries processed the urllib open URL request. A remote attacker could use this flaw to access sensitive information or cause a denial of service (excessive CPU and memory use) of a Python web application, processing URLs, via a specially-crafted urllib open URL request.
A flaw was reported [1] in Python's SimpleHTTPServer's listdirectory() function. Due to a missing charset parameter, if a user were to connect to SimpleHTTPServer using IE7, which engages in encoding-sniffing and can be tricked into interpretting the output as UTF7. Because of this, an attacker could hide <script> tags in UTF7-encoded characters which do not get quoted by cgi.encode(), allowing XSS attacks.
This has been corrected upstream in version 2.6.7rc2 [2], 2.5.6c1 [3]. It may be fixed in 2.7 as well, but I was unable to find a commit to match it against.
[1] http://bugs.python.org/issue11442 [2] http://svn.python.org/view/python/branches/release26-maint/Lib/SimpleHTTPServer.py?r1=66717&r2=88831&view=patch [3] http://svn.python.org/view/python/branches/release25-maint/Lib/SimpleHTTPServer.py?r1=53148&r2=88815&view=patch
Multiple integer overflows in the PyOSvsnprintf function in Python/mysnprintf.c in Python 2.5.2 and earlier allow context-dependent attackers to cause a denial of service (memory corruption) or have unspecified other impact via crafted input to string formatting operations. NOTE: the handling of certain integer values is also affected by related integer underflows and an off-by-one error.
Integer overflow in hashopenssl.c in the hashlib module in Python 2.5.2 and earlier might allow context-dependent attackers to defeat cryptographic digests, related to "partial hashlib hashing of data exceeding 4GB."
Multiple integer overflows in Python 2.5.2 and earlier allow context-dependent attackers to have an unknown impact via vectors related to the (1) stringobject, (2) unicodeobject, (3) bufferobject, (4) longobject, (5) tupleobject, (6) stropmodule, (7) gcmodule, and (8) mmapmodule modules. NOTE: The expandtabs integer overflows in stringobject and unicodeobject in 2.5.2 are covered by CVE-2008-5031.
Python 2.5.2 and earlier allows context-dependent attackers to execute arbitrary code via multiple vectors that cause a negative size value to be provided to the PyStringFromStringAndSize function, which allocates less memory than expected when assert() is disabled and triggers a buffer overflow.
Integer signedness error in the zlib extension module in Python 2.5.2 and earlier allows remote attackers to execute arbitrary code via a negative signed integer, which triggers insufficient memory allocation and a buffer overflow.