CVE-2018-1000030

Python 2.7.14 is vulnerable to a Heap-Buffer-Overflow as well as a
Heap-Use-After-Free. Python versions prior to 2.7.14 may also be vulnerable
and it appears that Python 2.7.17 and prior may also be vulnerable however
this has not been confirmed. The vulnerability lies when multiply threads
are handling large amounts of data. In both cases there is essentially a
race condition that occurs. For the Heap-Buffer-Overflow, Thread 2 is
creating the size for a buffer, but Thread1 is already writing to the
buffer without knowing how much to write. So when a large amount of data is
being processed, it is very easy to cause memory corruption using a
Heap-Buffer-Overflow. As for the Use-After-Free,
Thread3->Malloc->Thread1->Free’s->Thread2-Re-uses-Free’d Memory. The PSRT
has stated that this is not a security vulnerability due to the fact that
the attacker must be able to run code, however in some situations, such as
function as a service, this vulnerability can potentially be used by an
attacker to violate a trust boundary, as such the DWF feels this issue
deserves a CVE.

Bugs

• <https://bugs.python.org/issue31530&gt;
• <https://bugs.python.org/msg309265&gt;

Notes