Linux Kernel up to 4.x KSM information disclosure ⚔ [Disputed]

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 4.x. It has been classified as problematic. Impacted is an unknown function of the component KSM. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2015-2877. The attack is possible to be carried out remotely. No exploit exists. There is ongoing doubt regarding the real existence of this vulnerability. It is recommended to change the configuration settings.

Detailsinfo

A vulnerability was found in Linux Kernel up to 4.x (Operating System). It has been rated as problematic. This issue affects an unknown code block of the component KSM. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

** DISPUTED ** Kernel Samepage Merging (KSM) in the Linux kernel 2.6.32 through 4.x does not prevent use of a write-timing side channel, which allows guest OS users to defeat the ASLR protection mechanism on other guest OS instances via a Cross-VM ASL INtrospection (CAIN) attack. NOTE: the vendor states "Basically if you care about this attack vector, disable deduplication." Share-until-written approaches for memory conservation among mutually untrusting tenants are inherently detectable for information disclosure, and can be classified as potentially misunderstood behaviors rather than vulnerabilities.

The bug was discovered 08/05/2015. The weakness was disclosed 03/03/2017 by Antonio Barresi, Kaveh Razavi, Mathias Payer and Thomas R. Gross as confirmed advisory (CERT.org). It is possible to read the advisory at kb.cert.org. The identification of this vulnerability is CVE-2015-2877 since 04/03/2015. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 2732 days. During that time the estimated underground price was around $5k-$25k. The real existence of this vulnerability is still doubted at the moment.

It is possible to mitigate the problem by applying the configuration setting Disable Memory Deduplication.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 76256†). Be aware that VulDB is the high quality source for vulnerability data.

Not Affected

  • Linux Kernel up to 2.6.31

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.4

VulDB Base Score: 5.6
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 3.3
NVD Vector: 🔍

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Researcher Base Score: 🔍
NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Config
Status: 🔍

0-Day Time: 🔍

Config: Disable Memory Deduplication

Timelineinfo

09/09/2009 🔍
04/03/2015 +2032 days 🔍
07/12/2015 +100 days 🔍
08/05/2015 +24 days 🔍
08/05/2015 +0 days 🔍
03/03/2017 +576 days 🔍
03/03/2017 +0 days 🔍
03/03/2017 +0 days 🔍
11/12/2024 +2811 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: kb.cert.org
Researcher: Antonio Barresi, Kaveh Razavi, Mathias Payer, Thomas R. Gross
Status: Confirmed
Disputed: 🔍

CVE: CVE-2015-2877 (🔍)
GCVE (CVE): GCVE-0-2015-2877
GCVE (VulDB): GCVE-100-97487
CERT: 🔍
SecurityFocus: 76256 - Kernel Virtual Machine CVE-2015-2877 Memory Corruption Vulnerability
OSVDB: - CVE-2015-2877 - Linux - Cross-VM ASL INtrospection Issue

Entryinfo

Created: 03/03/2017 15:32
Updated: 11/12/2024 15:22
Changes: 03/03/2017 15:32 (70), 09/03/2020 16:45 (8), 08/06/2024 10:14 (18), 11/12/2024 15:22 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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