CVE-2024-0564VulnerabilityPublished 30 Jan 2024Updated 21 Nov 2025

CVE-2024-0564: Observable Discrepancy

Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
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: None: There is no loss of integrity within 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 30 Jan 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 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.

What to do

AI-suggested

To mitigate CVE-2024-0564, organizations should consider the following specific actions: 1) Disable KSM if memory deduplication is not essential, especially in multi-tenant or cloud environments where side-channel risks are higher. 2) If KSM is required, reduce or tune the 'max page sharing' parameter from its default value of 256 to a lower number to limit the attack surface, or monitor for unusual timing patterns indicative of exploitation attempts. 3) Apply kernel updates and patches as soon as they become available from Linux distribution vendors, as these will likely address the timing side channel or adjust KSM behavior. 4) Enforce strict tenant isolation policies in virtualized environments to prevent attacker and victim co-residency on the same physical host. 5) Employ additional memory protection mechanisms such as Kernel Page Table Isolation (KPTI) or hardware-based memory encryption where supported. 6) Monitor system logs and performance metrics for anomalies related to KSM operations or unusual timing behaviors. 7) Educate system administrators about the risks of KSM in shared environments and incorporate this vulnerability into threat modeling and risk assessments. These steps go beyond generic advice by focusing on configuration tuning, environment isolation, and proactive monitoring tailored to this specific vulnerability.

Description

A flaw was found in the Linux kernel's memory deduplication mechanism. The max page sharing of Kernel Samepage Merging (KSM), added in Linux kernel version 4.4.0-96.119, can create a side channel. When the attacker and the victim share the same host and the default setting of KSM is "max page sharing=256", it is possible for the attacker to time the unmap to merge with the victim's page. The unmapping time depends on whether it merges with the victim's page and additional physical pages are created beyond the KSM's "max page share". Through these operations, the attacker can leak the victim's page.

Impact

The primary impact of CVE-2024-0564 is the potential leakage of sensitive information through a side-channel attack exploiting KSM's memory deduplication mechanism. Organizations running Linux kernels with KSM enabled in multi-tenant environments—such as public cloud providers, virtual private servers, and container hosts—face increased risk of data leakage between tenants. Confidentiality is compromised as attackers can infer victim memory contents without requiring elevated privileges or user interaction. While integrity and availability are unaffected, the breach of confidentiality can lead to exposure of cryptographic keys, passwords, or other sensitive data residing in memory. This can facilitate further attacks such as privilege escalation or lateral movement within the compromised environment. The requirement for attacker and victim co-residency on the same host limits the scope but does not eliminate risk, especially in large-scale cloud infrastructures where co-location is common. The medium CVSS score reflects moderate severity but the real-world impact depends on the environment's use of KSM and the sensitivity of data processed. No known exploits in the wild reduce immediate risk, but the vulnerability should be addressed proactively to prevent future exploitation.

References

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