Pidgin Security Advisory

TitleGroupware message receive integer overflow
CVE NameCVE-2004-0754
Discovered BySean ("infamous42md")
SummaryCarefully crafted messages could cause a buffer overflow.
DescriptionInteger overflow in memory allocation results in heap overflow. By passing the size variable as ~0, integer overflows to 0 when 1 is added in g_alloc(). a malloc(0) call results in 16 bytes of memory being allocated on IA- 32. Then we can overflow the heap when nm_read_all() is called next step. usually cases like this suck for exploitation, because the len (~0) is so large that a following call to memcpy() or strcpy() will just run into kernel mem or unmapped address and fault. however in this case we read the data from the network via a read() call, so we can just stop sending data and close the connection to short out before ~0 bytes are read. however, this is triggered by input from the server, not directly from a client. someone running a malicious groupware server could leverage this to run arbitrary code on the client.
Fixed in Version0.82
FixBounds checking was added.

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