ALAS-2014-380


Amazon Linux AMI Security Advisory: ALAS-2014-380
Advisory Release Date: 2014-09-19 10:51 Pacific
Severity: Medium
References: CVE-2014-4616 

Issue Overview:

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.


Affected Packages:

python27


Issue Correction:
Run yum update python27 to update your system.

New Packages:
i686:
    python27-tools-2.7.5-13.35.amzn1.i686
    python27-2.7.5-13.35.amzn1.i686
    python27-test-2.7.5-13.35.amzn1.i686
    python27-debuginfo-2.7.5-13.35.amzn1.i686
    python27-libs-2.7.5-13.35.amzn1.i686
    python27-devel-2.7.5-13.35.amzn1.i686

src:
    python27-2.7.5-13.35.amzn1.src

x86_64:
    python27-tools-2.7.5-13.35.amzn1.x86_64
    python27-libs-2.7.5-13.35.amzn1.x86_64
    python27-test-2.7.5-13.35.amzn1.x86_64
    python27-2.7.5-13.35.amzn1.x86_64
    python27-devel-2.7.5-13.35.amzn1.x86_64
    python27-debuginfo-2.7.5-13.35.amzn1.x86_64