Strix
26.1K

CVE-2023-29383

LOWCVSS 3.3/10EPSS 0.43%

Last modified

CVE-2023-29383 is a low-severity vulnerability rated 3.3/10 on the CVSS scale. 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. EPSS estimates a 0.43% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
3.3/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability
0.43%

34.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
Shadow ProjectShadow4.13

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-29383?
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.
How severe is CVE-2023-29383?
CVE-2023-29383 has a CVSS score of 3.3/10 (LOW severity). The EPSS model estimates a 0.43% probability of exploitation in the next 30 days.
How do I fix CVE-2023-29383?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2023

View all 2023CVEs →

Are you affected by CVE-2023-29383?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST