inetutils: Inclusion of Functionality from Untrusted Control Sphere
CVE-2026-28372 is a high-severity inclusion of functionality from untrusted control sphere vulnerability in inetutils from GNU, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected inetutils versions: 2.7 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.41% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of inetutils you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.4 | High | CNA (mitre.org) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
telnetd in GNU inetutils through 2.7 allows privilege escalation that can be exploited by abusing systemd service credentials support added to the login(1) implementation of util-linux in release 2.40. This is related to client control over the CREDENTIALS_DIRECTORY environment variable, and requires an unprivileged local user to create a login.noauth file.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Inclusion of Functionality from Untrusted Control Sphere
The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.
How developers prevent this class of flaw
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to inbox.txt and ID 2 could map to profile.txt. Features such as the ESAPI AccessReferenceMap provide this capability.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Inclusion of Functionality from Untrusted Control Sphere vulnerabilities (CWE-829)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Third-party and government advisories
- lists.gnu.org/archive/html/bug-inetutils/2026-02/msg00012.htmlMailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/02/24/1Mailing List, Third Party Advisory
- openwall.com/lists/oss-security/2026/02/27/3Mailing List, Third Party Advisory
Technical write-ups (may include proof of concept)
- lists.gnu.org/archive/html/bug-inetutils/2026-02/msg00000.htmlExploit, Mailing List, Third Party Advisory
Other references
Other vulnerabilities in inetutils
- 9.8 Critical severity
- 9.8 Critical severity
GNU InetUtils Argument Injection Exploited
- 7.8 High severity
- 7.5 High severity
Recent Inclusion of Functionality from Untrusted Control Sphere vulnerabilities
- 9.9 Critical severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
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