VulnerabilityPublished 4 Feb 2024Updated 8 Nov 2025

CVE-2023-6240: Red Hat Enterprise Linux 8 · Observable Discrepancy

Affects Red Hat Enterprise Linux 8Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 61% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
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: 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 4 Feb 2024
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 26 Oct 2026.

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

AI-suggested

Organizations should prioritize applying official kernel patches from Red Hat as soon as they become available to address this vulnerability. In the interim, administrators should audit and minimize the exposure of services using RSA private keys on affected systems, possibly disabling or restricting network access to vulnerable services. Employing cryptographic best practices such as rotating RSA keys, using stronger or alternative cryptographic algorithms (e.g., ECC-based keys), and implementing hardware security modules (HSMs) to isolate private key operations can reduce risk. Monitoring network traffic for anomalous patterns indicative of side-channel attacks and enhancing logging around cryptographic operations may aid in early detection. Additionally, organizations should review their incident response plans to prepare for potential exploitation scenarios and ensure timely communication with stakeholders.

Description

A Marvin vulnerability side-channel leakage was found in the RSA decryption operation in the Linux Kernel. This issue may allow a network attacker to decrypt ciphertexts or forge signatures, limiting the services that use that private key.

Impact

For European organizations, the vulnerability poses a risk to the confidentiality of sensitive data protected by RSA encryption on Red Hat Enterprise Linux 8 systems. Services such as VPNs, SSH, TLS/SSL endpoints, and other cryptographic authentication mechanisms that rely on RSA private keys could be compromised, allowing attackers to decrypt intercepted communications or forge signatures to impersonate legitimate entities. This could lead to data breaches, unauthorized access, and erosion of trust in secure communications. The limited integrity impact suggests that while forging signatures is possible, the scope is constrained. The absence of availability impact means systems remain operational but potentially compromised. Given the widespread use of Red Hat Enterprise Linux in enterprise and government sectors across Europe, especially in critical infrastructure, finance, and telecommunications, this vulnerability could have significant operational and reputational consequences if exploited.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Nov 2025, 07:34 UTC

Technical details

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