Improper Link Resolution Before File Access ('Link Following')
HashiCorp go-slug up to 0.4.3 did not fully protect against directory traversal while unpacking tar archives, and protections could be bypassed with specific constructions of multiple symlinks. Fixed in 0.5.0.
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.