CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

A vulnerability was found in Linux Kernel up to 4.17.3 (Operating System). It has been declared as problematic. This vulnerability affects the function siginfo::si_overrun of the file kernel/time/posix-timers.c of the component POSIX Timer. The manipulation with an unknown input leads to a integer overflow vulnerability. The CWE definition for the vulnerability is CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.

The bug was discovered 06/22/2018. The weakness was presented 07/02/2018 (Website). The advisory is shared for download at bugzilla.kernel.org. This vulnerability was named CVE-2018-12896 since 06/26/2018. The attack needs to be approached locally. The successful exploitation requires a single authentication. There are known technical details, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 10 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 111243 (Fedora 27 : kernel (2018-8484550fff)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 157818 (Oracle Enterprise Linux Security Update for Unbreakable Enterprise kernel (ELSA-2018-4242)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 2 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (111243). See 115041, 119428, 120200 and 120201 for similar entries.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.17.0
• 4.17.1
• 4.17.2
• 4.17.3

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock
unlock	unlock	unlock	unlock	unlock	unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Integer overflow
CWE: CWE-190 / CWE-189
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	unlock	unlock	unlock	unlock
Today	unlock	unlock	unlock	unlock

Nessus ID: 111243
Nessus Name: Fedora 27 : kernel (2018-8484550fff)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: github.com

Timelineinfo

06/22/2018 🔍
06/26/2018 +4 days 🔍
07/02/2018 +5 days 🔍
07/02/2018 +0 days 🔍
07/03/2018 +1 days 🔍
07/13/2018 +10 days 🔍
07/24/2018 +11 days 🔍
02/15/2019 +206 days 🔍
03/29/2023 +1503 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: FEDORA-2018-8484550fff
Status: Confirmed

CVE: CVE-2018-12896 (🔍)
SecurityFocus: 107127 - Linux Kernel CVE-2019-6974 Security Bypass Vulnerability

See also: 🔍

Entryinfo

Created: 07/03/2018 07:50
Updated: 03/29/2023 15:11
Changes: 07/03/2018 07:50 (76), 02/23/2020 16:49 (6), 03/29/2023 15:05 (5), 03/29/2023 15:11 (1)
Complete: 🔍
Cache ID: 18:C72:103

Discussion

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