Fix out-of-path check for benign symlinks #36
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woefe
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I'm not 100% sure that this proposed fix also mitigates CVE-2020-36193. It's probably a good idea to consult whoever reported that vulnerability to you. |
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Nope, this does not fix CVE-2020-36193 🙈. |
woefe
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Okay, now I think its fine |
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Thanks for taking a look at this @woefe! I'll review it later this week. |
mrook
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A symlink is out-of-path if it is an absolute path or goes "up" too many times. This checks how deep the filename is and whether the link points more levels up than the depth of the filename.
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@woefe |
mrook
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As far as I understand the problem in #35, a symlink is "out-of-path" if it is an absolute path or goes "up" too many times. This proposed fix checks the amount of ".." vs. normal downward path elements (excluding "." and "").