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

CVE-2020-26277

Severity Medium
Score 6.1/10

Summary

DBdeployer is a tool that deploys MySQL database servers easily. In DBdeployer before version 1.58.2, users unpacking a tarball may use a maliciously packaged tarball that contains symlinks to files external to the target. In such scenario, an attacker could induce dbdeployer to write into a system file, thus altering the computer defenses. For the attack to succeed, the following factors need to contribute: 1) The user is logged in as root. While dbdeployer is usable as root, it was designed to run as unprivileged user. 2) The user has taken a tarball from a non secure source, without testing the checksum. When the tarball is retrieved through dbdeployer, the checksum is compared before attempting to unpack. This has been fixed in version 1.58.2.

  • HIGH
  • NETWORK
  • HIGH
  • CHANGED
  • REQUIRED
  • 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.

References

Advisory Timeline

  • Published