CVE-2025-4437VulnerabilityPublished 20 Aug 2025Updated 1 Sep 2026

CVE-2025-4437: Red Hat OpenShift Container Platform 4 · Unthrottled Resource Allocation

Affects Red Hat OpenShift Container Platform 4Source CVE Database V5

Not known to be exploited · CVSS 5.7 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.7Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Aug 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 2026-10-26.

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.

cwe-770

What to do

AI-suggested

To mitigate CVE-2025-4437, organizations should take the following specific actions: 1) Monitor and audit container images and runtime environments to ensure /etc/passwd files are of reasonable size and do not contain excessive entries that could trigger high memory usage. 2) Implement strict admission controls and policies to restrict the ability of users to launch containers with arbitrary or non-existent runAsUser values, limiting privilege escalation or misuse. 3) Apply any vendor-provided patches or updates from Red Hat addressing this vulnerability as soon as they become available. 4) Use resource quotas and limits at the Kubernetes/OpenShift level to constrain memory usage per pod and node, reducing the impact of memory exhaustion events. 5) Employ runtime monitoring and alerting to detect unusual memory consumption patterns on nodes hosting OpenShift workloads. 6) Consider isolating critical workloads on dedicated nodes to minimize collateral impact from DoS caused by other containers. 7) Educate developers and operators about the risks of specifying non-existent users in security contexts and enforce best practices for container user management. These measures combined will reduce the likelihood and impact of exploitation beyond generic advice.

Description

There's a vulnerability in the CRI-O application where when container is launched with securityContext.runAsUser specifying a non-existent user, CRI-O attempts to create the user, reading the container's entire /etc/passwd file into memory. If this file is excessively large, it can cause the a high memory consumption leading applications to be killed due to out-of-memory. As a result a denial-of-service can be achieved, possibly disrupting other pods and services running in the same host.

Impact

The primary impact of CVE-2025-4437 is denial-of-service through resource exhaustion on hosts running Red Hat OpenShift Container Platform 4 with CRI-O. Excessive memory consumption can cause the kernel or container runtime to kill processes, disrupting not only the targeted container but also other pods and services sharing the same node. This can degrade cluster availability and reliability, potentially affecting critical workloads and business operations. In multi-tenant environments, an attacker with container launch privileges could intentionally trigger this condition to disrupt other tenants. While confidentiality and integrity are not affected, the availability impact can be significant, especially in production environments with high workload density. The requirement for privileges and user interaction limits the attack surface but does not eliminate risk in environments where users can deploy containers with custom security contexts. Organizations relying on OpenShift 4 for container orchestration should consider this vulnerability a moderate operational risk that could lead to service outages and increased operational overhead for remediation and recovery.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 27 Feb 2026, 14:33 UTC

Technical details

References

Community reviews

Related threats