CVE-2016-8617

Source
Severity High
Remote Yes
Type Arbitrary code execution
Description
In libcurl's base64 encode function, the output buffer is allocated as follows without any checks on insize:

malloc( insize * 4 / 3 + 4 )
On systems with 32-bit addresses in userspace (e.g. x86, ARM, x32), the multiplication in the expression wraps around if insize is at least 1GB of data. If this happens, an undersized output buffer will be allocated, but the full result will be written, thus causing the memory behind the output buffer to be overwritten.

If a username is set directly via CURLOPT_USERNAME (or curl's -u, --user option), this vulnerability can be triggered. The name has to be at least 512MB big in a 32bit system.

Systems with 64 bit versions of the size_t type are not affected by this issue.
Group Package Affected Fixed Severity Status Ticket
AVG-66 lib32-libcurl-gnutls 7.50.3-1 7.51.0-1 High Fixed
AVG-65 libcurl-gnutls 7.50.3-1 7.51.0-1 High Fixed
AVG-63 lib32-libcurl-compat 7.50.3-1 7.51.0-1 High Fixed
AVG-62 libcurl-compat 7.50.3-1 7.51.0-1 High Fixed
AVG-61 lib32-curl 7.50.3-1 7.51.0-1 High Fixed
AVG-60 curl 7.50.3-1 7.51.0-1 High Fixed
Date Advisory Group Package Severity Description
03 Nov 2016 ASA-201611-9 AVG-65 libcurl-gnutls High multiple issues
03 Nov 2016 ASA-201611-8 AVG-62 libcurl-compat High multiple issues
03 Nov 2016 ASA-201611-7 AVG-60 curl High multiple issues
02 Nov 2016 ASA-201611-5 AVG-63 lib32-libcurl-compat High multiple issues
02 Nov 2016 ASA-201611-4 AVG-61 lib32-curl High multiple issues
03 Nov 2016 ASA-201611-10 AVG-66 lib32-libcurl-gnutls High multiple issues
References
https://curl.haxx.se/docs/adv_20161102C.html