CVE-2025-5689VulnerabilityPublished 16 Jun 2025Updated 17 Jun 2025

CVE-2025-5689: Canonical authd · Vulnerability

Affects Canonical authdSource CVE Database V5

Not known to be exploited · CVSS 8.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

8.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHububuntu/authd`pkg:github/ubuntu/authd`Other threats	Affected =0.0.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediate mitigation should focus on restricting first-time SSH logins or monitoring them closely for anomalous privilege escalations. 2. Implement strict access controls and multi-factor authentication (MFA) to reduce the risk of unauthorized credential use. 3. Employ session monitoring and logging to detect unusual group membership or privilege changes during SSH sessions, particularly for new users. 4. Use network segmentation to limit the impact of any compromised session with elevated privileges. 5. Until a patch is available, consider disabling or restricting the use of the affected authd component if feasible, or use alternative authentication mechanisms. 6. Regularly audit user group memberships and SSH session privileges to identify and remediate any unauthorized root group assignments. 7. Stay updated with Canonical’s advisories for patches or official workarounds and apply them promptly once released. 8. Conduct penetration testing focused on SSH authentication flows to identify potential exploitation paths related to this vulnerability.

Description

A flaw was found in the temporary user record that authd uses in the pre-auth NSS. As a result, a user login for the first time will be considered to be part of the root group in the context of that SSH session.

Impact

For European organizations, this vulnerability poses a significant risk particularly to those relying on Canonical's authd component within their SSH authentication infrastructure. Since SSH is widely used for remote administration and access to servers, the incorrect assignment of root group privileges during initial login could allow attackers or malicious insiders to gain elevated access rights, compromising system confidentiality and integrity. This could lead to unauthorized data access, modification, or lateral movement within networks. Organizations in sectors such as finance, government, critical infrastructure, and technology that depend on secure SSH access are especially vulnerable. The scope change indicated by the CVSS vector means that the vulnerability can affect resources beyond the initially compromised component, potentially impacting multiple systems if the attacker leverages the elevated privileges. Although no known exploits exist yet, the low complexity and network accessibility make it likely that attackers will develop exploits, increasing risk over time. The vulnerability does not affect availability directly but could indirectly cause service disruptions if exploited to modify system configurations or escalate privileges maliciously.

CWE-269Improper Privilege Management (opens in a new tab)
Class weaknessLikelihood of exploit: MediumOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Follow the principle of least privilege when assigning access rights to entities in a software system.
Architecture and Design · Separation of Privilege
Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
Third Party Javascript Management (opens in a new tab)
Virtual Patching (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
V1.10.1 (opens in a new tab)
Attack patterns
Restful Privilege Elevation (opens in a new tab)
Privilege Abuse (opens in a new tab)
Privilege Escalation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/ubuntu/authd/security/advisories/GHSA-g8qw-mgjx-rwjr (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Jun 2025, 12:05 UTC

WeaknessesCWE-269

Technical details

References

Community reviews

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