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Improper Link Resolution Before File Access ('Link Following')

CVE-2020-27833

Severity High
Score 7.1/10

Summary

A Zip Slip vulnerability was found in the oc binary in openshift-clients where an arbitrary file write is achieved by using a specially crafted raw container image (.tar file) which contains symbolic links. The vulnerability is limited to the command `oc image extract`. If a symbolic link is first created pointing within the tarball, this allows further symbolic links to bypass the existing path check. This flaw allows the tarball to create links outside the tarball's parent directory, allowing for executables or configuration files to be overwritten, resulting in arbitrary code execution. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. Versions up to and including openshift-clients-4.7.0-202104250659.p0.git.95881af are affected.

  • HIGH
  • NETWORK
  • HIGH
  • UNCHANGED
  • REQUIRED
  • LOW
  • HIGH
  • HIGH

CWE-59 - Improper Link Resolution Before File Access

'Improper link resolution before file access' occurs when software accesses a file resource but fails to verify that the file isn't a link or shortcut to another file. An attacker can potentially gain access to arbitrary files and from there the impact can vary, depending on the application, from sensitive data exposure to remote code execution.

Advisory Timeline

  • Published