Out-of-bounds Read in Shadow Project
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Shadow Project — versions 4.13
Weakness classification (CWE)
Public proof-of-concept exploits
- GrigGM/05-virt-04-docker-hw
- Jidendiran-coder/trivy-grafana-alert-system
- Myash-New/05-virt-04-docker-in-practice
- OzNetNerd/CheckovOutputProcessor
- Telooss/TP-WIK-DPS-TP02
- XXRadeonXFX/trivy-grafana-ai-alert-automation
- adegoodyer/kubernetes-admin-toolkit
- drewtwitchell/scancompare
- fokypoky/places-list
- mmbazm/secure_
References
- github.com/shadow-maint/shadow/pull/687 (Issue Tracking)
- github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d (Patch)
- www.trustwave.com/en-us/resources/security-resources/security-advisories/ (Exploit, Third Party Advisory)
- www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-… (Exploit, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-29383?
- CVE-2023-29383 is a low-severity vulnerability in Shadow Project, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 3.3/10. Published 2023-04-14.
- How severe is CVE-2023-29383?
- Low severity. CVSS v3 base score is 3.3 out of 10.
- Is CVE-2023-29383 known to be exploited?
- 13 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.