{"id":"UBUNTU-CVE-2023-29383","details":"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.","modified":"2025-10-24T05:01:54Z","published":"2023-04-14T22:15:00Z","upstream":["CVE-2023-29383"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2023-29383"},{"type":"REPORT","url":"https://github.com/shadow-maint/shadow/pull/687"},{"type":"REPORT","url":"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797"},{"type":"REPORT","url":"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2023-29383"}],"affected":[{"package":{"name":"shadow","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/shadow@1:4.1.5.1-1ubuntu9.5+esm4?arch=source&distro=esm-infra-legacy/trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.5.1-1ubuntu6","1:4.1.5.1-1ubuntu7","1:4.1.5.1-1ubuntu8","1:4.1.5.1-1ubuntu9","1:4.1.5.1-1ubuntu9.1","1:4.1.5.1-1ubuntu9.2","1:4.1.5.1-1ubuntu9.4","1:4.1.5.1-1ubuntu9.5","1:4.1.5.1-1ubuntu9.5+esm1","1:4.1.5.1-1ubuntu9.5+esm2","1:4.1.5.1-1ubuntu9.5+esm3","1:4.1.5.1-1ubuntu9.5+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"login","binary_version":"1:4.1.5.1-1ubuntu9.5+esm4"},{"binary_name":"passwd","binary_version":"1:4.1.5.1-1ubuntu9.5+esm4"},{"binary_name":"uidmap","binary_version":"1:4.1.5.1-1ubuntu9.5+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-29383.json"}},{"package":{"name":"shadow","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/shadow@1:4.2-3.1ubuntu5.5+esm4?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.1.5.1-1.1ubuntu7","1:4.2-3.1ubuntu1","1:4.2-3.1ubuntu2","1:4.2-3.1ubuntu3","1:4.2-3.1ubuntu4","1:4.2-3.1ubuntu5","1:4.2-3.1ubuntu5.2","1:4.2-3.1ubuntu5.3","1:4.2-3.1ubuntu5.4","1:4.2-3.1ubuntu5.5+esm1","1:4.2-3.1ubuntu5.5+esm2","1:4.2-3.1ubuntu5.5+esm3","1:4.2-3.1ubuntu5.5+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"login","binary_version":"1:4.2-3.1ubuntu5.5+esm4"},{"binary_version":"1:4.2-3.1ubuntu5.5+esm4","binary_name":"passwd"},{"binary_version":"1:4.2-3.1ubuntu5.5+esm4","binary_name":"uidmap"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-29383.json"}},{"package":{"name":"shadow","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/shadow@1:4.5-1ubuntu2.5+esm1?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.2-3.2ubuntu4","1:4.5-1ubuntu1","1:4.5-1ubuntu2","1:4.5-1ubuntu2.2","1:4.5-1ubuntu2.3","1:4.5-1ubuntu2.4","1:4.5-1ubuntu2.5","1:4.5-1ubuntu2.5+esm1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:4.5-1ubuntu2.5+esm1","binary_name":"login"},{"binary_version":"1:4.5-1ubuntu2.5+esm1","binary_name":"passwd"},{"binary_name":"uidmap","binary_version":"1:4.5-1ubuntu2.5+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-29383.json"}},{"package":{"name":"shadow","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/shadow@1:4.8.1-1ubuntu5.20.04.5?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.5-1.1ubuntu4","1:4.8-1ubuntu1","1:4.8.1-1ubuntu1","1:4.8.1-1ubuntu2","1:4.8.1-1ubuntu3","1:4.8.1-1ubuntu4","1:4.8.1-1ubuntu5","1:4.8.1-1ubuntu5.20.04","1:4.8.1-1ubuntu5.20.04.1","1:4.8.1-1ubuntu5.20.04.2","1:4.8.1-1ubuntu5.20.04.3","1:4.8.1-1ubuntu5.20.04.4","1:4.8.1-1ubuntu5.20.04.5"],"ecosystem_specific":{"binaries":[{"binary_name":"login","binary_version":"1:4.8.1-1ubuntu5.20.04.5"},{"binary_name":"passwd","binary_version":"1:4.8.1-1ubuntu5.20.04.5"},{"binary_name":"uidmap","binary_version":"1:4.8.1-1ubuntu5.20.04.5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-29383.json"}},{"package":{"name":"shadow","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/shadow@1:4.8.1-2ubuntu2.2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:4.8.1-1ubuntu9","1:4.8.1-1ubuntu10","1:4.8.1-2ubuntu1","1:4.8.1-2ubuntu2","1:4.8.1-2ubuntu2.1","1:4.8.1-2ubuntu2.2"],"ecosystem_specific":{"binaries":[{"binary_name":"login","binary_version":"1:4.8.1-2ubuntu2.2"},{"binary_name":"passwd","binary_version":"1:4.8.1-2ubuntu2.2"},{"binary_name":"uidmap","binary_version":"1:4.8.1-2ubuntu2.2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-29383.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"low"}]}