Closed
Description
Expected behavior
Poco::Net::MailMessage::read finishes when reading messages without final multipart boundary.
Actual behavior
Process stucks in infinite loop with 100% CPU consumption on reading with following strace:
read(3, "\n", 8191) = 1
read(3, "", 8191) = 0
read(3, "", 8191) = 0
lseek(3, -1, SEEK_CUR) = 7252
read(3, "\n", 8191) = 1
read(3, "", 8191) = 0
read(3, "", 8191) = 0
lseek(3, -1, SEEK_CUR) = 7252
Steps to reproduce the problem
- Compile and run the following program:
#include "Net/MailMessage.h"
#include <fstream>
int main() {
std::ifstream ifs("mail_example.txt");
Poco::Net::MailMessage message;
message.read(ifs);
return 0;
}
with mail_example.txt containing the following:
To: user@example.org
Subject: Test parsing incomplete multipart message
X-Mailer: Microsoft Office Outlook, Build 17.551210
From: user@examle.com
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="ec3ac6be4c8e86c0d91b89466e1f7bd7"
Date: Mon, 23 Jul 2018 14:29:45 +0200 (CEST)
Content-Transfer-Encoding: 7bit
This is a MIME encoded message.
--ec3ac6be4c8e86c0d91b89466e1f7bd7
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: 8bit
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head> <title>Looks like outlook sends such emails sometimes</title> </head>
<body>
<div><span style="background-color: #ffffff; color: #0000ff;"><strong></strong></span></div>
</body>
</html>
POCO version
1.9.0
Compiler and version
GCC 6.3.0
Operating system and version
CentOS 7.5
Other relevant information
Root cause: MessageHeader::read incorrectly puts eof into istream which results in storing char 255 in stream.
Patch:
--- ./Net/src/MessageHeader.cpp.orig 2018-03-08 21:28:06.000000000 +0700
+++ ./Net/src/MessageHeader.cpp 2018-07-24 18:22:55.623781305 +0700
@@ -104,7 +104,9 @@
add(name, decodeWord(value));
++fields;
}
- istr.putback(ch);
+ if (ch != eof) {
+ istr.putback(ch);
+ }
}
P.S.
During investigation some emails with X-Mailer: Microsoft Office Outlook, Build 17.551210 which causes process hanging were found.
Maybe they were sent by Outlook (but I cannot check it).