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

CVE-2019-13173

Severity High
Score 7.5/10

Summary

fstream before 1.0.12 is vulnerable to Arbitrary File Overwrite. Extracting tarballs containing a hardlink to a file that already exists in the system, and a file that matches the hardlink, will overwrite the system's file with the contents of the extracted file. The fstream.DirWriter() function is vulnerable.

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