An issue was discovered in shadow 4.5.
An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used "group blacklisting" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.
- Published
- Feb 15, 2018
- Updated
- Jun 16, 2026
- EPSS
- 1.6% · 74th percentile
- CWE
- CWE-732
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.6%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| shadow project | shadow | cpe:2.3:a:shadow_project:shadow |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- shadow project shadow4.5
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | shadow | before 1:4.7-1 | 1:4.7-1 |
| openSUSE:Tumbleweed | shadow | before 4.9-1.1 | 4.9-1.1 |
| SUSE:Linux Enterprise Desktop 12 SP2 | shadow | before 4.2.1-27.6.1 | 4.2.1-27.6.1 |
Same product
shadow project: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-12424In shadow before 4.5, the newusers tool could be made to manipulate internal data structures in ways unintended by the authors.40Plan
- CVE-2019-19882shadow 4.8, in certain circumstances affecting at least Gentoo, Arch Linux, and Void Linux, allows local users to obtain root access because31Monitor
- CVE-2016-6252Integer overflow in shadow 4.2.1 allows local users to gain privileges via crafted input to newuidmap.31Monitor
- CVE-2023-29383In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger).13Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:shadow | 1:4.7-1 · Debian:12 | Package registry (OSV) |
| opensuse:shadow | 4.9-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| suse:shadow | 4.2.1-27.6.1 · SUSE:Linux Enterprise Desktop 12 SP2 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-732 · Incorrect Permission Assignment for Critical ResourceCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Accessing Functionality Not Properly Constrained by ACLsCAPEC-1likelihood: High · High
- Privilege AbuseCAPEC-122likelihood: High · Medium
- Directory IndexingCAPEC-127likelihood: High · Medium
- Using Malicious FilesCAPEC-17likelihood: High · Very High
- Exploiting Incorrectly Configured Access Control Security LevelsCAPEC-180likelihood: High · Medium
- Signing Malicious CodeCAPEC-206Very High
- Hijacking a privileged processCAPEC-234Medium
- Reusing Session IDs (aka Session Replay)CAPEC-60likelihood: High · High
ATT&CK techniques
- File and Directory DiscoveryT1083
- Access Token Manipulation:Token Impersonation/TheftT1134.001
- Server Software Component: Terminal Services DLLT1505.005
- Abuse Elevation Control MechanismT1548
- Use Alternate Authentication Material:Web Session CookieT1550.004
- Subvert Trust Controls:Code SigningT1553.002
- Compromise Client Software BinaryT1554
- Hijack Execution Flow:Executable Installer File Permissions WeaknessT1574.005
- Hijack Execution Flow: ServicesFile Permissions WeaknessT1574.010
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.