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Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVE-2023-29383

Low
3.3/10

Summary

In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that "cat /etc/passwd" shows a rogue user account.

  • LOW
  • LOCAL
  • LOW
  • UNCHANGED
  • NONE
  • LOW
  • NONE
  • NONE

CWE-74 - Injection

Listed as the number one web application security risk on the 'OWASP Top Ten', injection attacks are widespread and dangerous, especially in legacy applications. Injection attacks are a class of vulnerabilities in which an attacker injects untrusted data into a web application that gets processed by an interpreter, altering the program's execution. This can result in data loss/theft, loss of data integrity, denial of service, and even compromising the entire system.

References

Advisory Timeline

  • Published