Linux Kernel up to 4.3.3 security/keys/keyctl.c keyctl_read_key race condition

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability, which was classified as critical, has been found in Linux Kernel up to 4.3.3 (Operating System). This issue affects the function keyctl_read_key of the file security/keys/keyctl.c. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is availability.

The weakness was published 02/08/2016 with Google (Website). It is possible to read the advisory at The identification of this vulnerability is CVE-2015-7550 since 09/29/2015. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 87738 (Debian DLA-378-1 : linux-2.6 security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context local. The commercial vulnerability scanner Qualys is able to test this issue with plugin 168771 (SUSE Enterprise Linux Security update for the Linux Kernel (SUSE-SU-2016:1203-1)).

Upgrading to version 4.3.4 eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Vulnerability Center (SBV-56445) and Tenable (87738). Similar entries are available at 8569, 78541, 79223 and 79228.





CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.1

VulDB Base Score: 7.0
VulDB Temp Score: 6.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
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Class: Race condition
CWE: CWE-362
ATT&CK: Unknown

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

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EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Nessus ID: 87738
Nessus Name: Debian DLA-378-1 : linux-2.6 security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703434
OpenVAS Name: Debian Security Advisory DSA 3434-1 (linux - security update)
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Threat Intelligenceinfo

Interest: 🔍
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Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.3.4


09/29/2015 🔍
12/09/2015 +72 days 🔍
12/22/2015 +13 days 🔍
01/04/2016 +13 days 🔍
01/05/2016 +1 days 🔍
02/07/2016 +32 days 🔍
02/08/2016 +1 days 🔍
02/08/2016 +0 days 🔍
02/08/2016 +0 days 🔍
07/07/2022 +2340 days 🔍



Advisory: USN-2888-1
Organization: Google
Status: Not defined
Confirmation: 🔍

CVE: CVE-2015-7550 (🔍)

Vulnerability Center: 56445 - Linux Kernel before 4.3.4 Local DoS and Other Unspecified Impact due to a Race Condition in keyctl_read_key Function, Medium
SecurityFocus: 79903 - Linux Kernel CVE-2015-7550 Null Pointer Deference Local Denial of Service Vulnerability

See also: 🔍


Created: 02/08/2016 09:04 AM
Updated: 07/07/2022 07:32 AM
Changes: (5) vulnerability_cvss2_nvd_basescore vulnerability_cvss3_meta_tempscore advisory_identifier exploit_price_0day countermeasure_patch_url
Complete: 🔍


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