3.3 Low
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
4 Medium
AI Score
Confidence
High
1.7 Low
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:L/AC:L/Au:S/C:N/I:P/A:N
0.0004 Low
EPSS
Percentile
12.6%
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.
github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d
github.com/shadow-maint/shadow/pull/687
www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/
www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797
3.3 Low
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
4 Medium
AI Score
Confidence
High
1.7 Low
CVSS2
Access Vector
LOCAL
Access Complexity
LOW
Authentication
SINGLE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:L/AC:L/Au:S/C:N/I:P/A:N
0.0004 Low
EPSS
Percentile
12.6%