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Amazon Linux AMI: Security patch for python-simplejson (ALAS-2014-374) (CVE-2014-4616)

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Amazon Linux AMI: Security patch for python-simplejson (ALAS-2014-374) (CVE-2014-4616)



It was reported that Python built-in _json module have a flaw (insufficient bounds checking), which allows a local user to read current process' arbitrary memory.

Quoting the upstream bug report:

The sole prerequisites of this attack are that the attacker is able to control or influence the two parameters of the default scanstring function: the string to be decoded and the index.

The bug is caused by allowing the user to supply a negative index value. The index value is then used directly as an index to an array in the C code; internally the address of the array and its index are added to each other in order to yield the address of the value that is desired. However, by supplying a negative index value and adding this to the address of the array, the processor's register value wraps around and the calculated value will point to a position in memory which isn't within the bounds of the supplied string, causing the function to access other parts of the process memory.


  • amazon-linux-upgrade-python-simplejson
  • amazon-linux-upgrade-python-simplejson-debuginfo

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