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March 25, 2023Severity Medium Analysis Summary GandCrab – a ransomware-as-a-service variant – was discovered in early 2018. At least five versions of GandCrab have been created since its […]March 25, 2023Severity Medium Analysis Summary NjRat is a Remote Access Trojan, which is found leveraging Pastebin to deliver a second-stage payload after initial infection. There are multiple […]March 24, 2023Severity Medium Analysis Summary CVE-2023-20113 Cisco SD-WAN vManage Software is vulnerable to cross-site request forgery, caused by improper validation of user-supplied input. By persuading an authenticated […]Threat Insights
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
Connect with Us
Platform
Managed Security Services
Managed Penetration Testing
Rewterz penetration testing services help organizations determine if a cyber attacker can gain access to their critical assets while giving them detailed insights of the overall business impact of a cyber attack.
Resources
March 25, 2023Severity Medium Analysis Summary GandCrab – a ransomware-as-a-service variant – was discovered in early 2018. At least five versions of GandCrab have been created since its […]March 25, 2023Severity Medium Analysis Summary NjRat is a Remote Access Trojan, which is found leveraging Pastebin to deliver a second-stage payload after initial infection. There are multiple […]March 24, 2023Severity Medium Analysis Summary CVE-2023-20113 Cisco SD-WAN vManage Software is vulnerable to cross-site request forgery, caused by improper validation of user-supplied input. By persuading an authenticated […]Threat Insights
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
Connect with Us
Rewterz Threat Advisory – Microsoft Windows Server 2008 and Windows 7 multiple vulnerabilities
November 15, 2018Rewterz Threat Advisory – Microsoft Windows 8.1 Multiple Vulnerabilities
November 19, 2018
Malicious local users may gain escalated privileges to execute arbitrary code by exploiting a vulnerability in the Linux Kernel.
IMPACT: NORMAL
PUBLISH DATE: 16-11-2018
OVERVIEW
A security flaw in the Linux Kernel may be exploited by malicious local users to gain kernel privileges. It could then be used to induce a use-after-free condition on the system, or execute arbitrary code using Kernel privileges. Updates are available for all the affected versions of the product.
ANALYSIS
A race condition error within the “packet_do_bind()” function (net/packet/af_packet.c) can be exploited to trigger a use-after-free error. Successful exploitation may allow execution of arbitrary code with kernel privileges.
In the Linux kernel through 4.19, a use-after-free can occur due to a race condition between fanout_add from setsockopt and bind on an AF_PACKET socket. This issue exists because of the 15fe076edea787807a7cdc168df832544b58eba6 incomplete fix for a race condition.
The code mishandles a certain multithreaded case involving a packet_do_bind unregister action followed by a packet_notifier register action. Later, packet_release operates on only one of the two applicable linked lists. The attacker can achieve Program Counter control.
An unprivileged, local user could use this flaw to trigger kernel memory corruption, making the system crash or go unresponsive. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.
AFFECTED PRODUCTS
Linux Kernel 3.16.x
Linux Kernel 4.4.x
Linux Kernel 4.9.x
Linux Kernel 4.14.x
UPDATES
Update the following affected versions according to the suggested updates available.
Versions 4.14.x:
Update to version 4.14.7 or later.
Versions 4.9.x:
Update to version 4.9.70 or later.
Versions 4.4.x:
Update to version 4.4.106 or later.
Versions 3.16.x:
Update to version 3.16.55 or later.
If you think you are a victim of a cyber-attack, immediately send an e-mail to soc@rewterz.com.