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

CVE-2019-11251

Severity Medium
Score 5.7/10

Summary

The Kubernetes kubectl cp command in versions 1.1-1.12, and versions prior to 1.13.11, 1.14.7, and 1.15.4 allows a combination of two symlinks provided by tar output of a malicious container to place a file outside of the destination directory specified in the kubectl cp invocation. This could be used to allow an attacker to place a nefarious file using a symlink, outside of the destination tree.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • REQUIRED
  • LOW
  • NONE
  • NONE

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