Arbitrary File Write via Archive Extraction (Zip Slip)
Affecting dotnetzip package, versions [,1.11.0)
Report new vulnerabilitiesOverview
dotnetzip
is a class library and toolset for manipulating zip files.
Affected versions of the package are vulnerable to Arbitrary File Write via Archive Extraction (AKA "Zip Slip").
It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicous file will result in traversing out of the target folder, ending up in /root/.ssh/
overwriting the authorized_keys
file:
+2018-04-15 22:04:29 ..... 19 19 good.txt
+2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Remediation
Upgrade dotnetzip
to version 1.11.0 or higher.
References
CVSS Score
-
Attack VectorLocal
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Attack ComplexityLow
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Privileges RequiredNone
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User InteractionRequired
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ScopeUnchanged
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ConfidentialityNone
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IntegrityHigh
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AvailabilityNone
- Credit
- Snyk Security research Team
- CVE
- CVE-2018-1002205
- CWE
- CWE-29
- Snyk ID
- SNYK-DOTNET-DOTNETZIP-60245
- Disclosed
- 17 Apr, 2018
- Published
- 31 May, 2018