Headline
GameOver(lay): Two Severe Linux Vulnerabilities Impact 40% of Ubuntu Users
Cybersecurity researchers have disclosed two high-severity security flaws in the Ubuntu kernel that could pave the way for local privilege escalation attacks. Cloud security firm Wiz, in a report shared with The Hacker News, said the easy-to-exploit shortcomings have the potential to impact 40% of Ubuntu users. "The impacted Ubuntu versions are prevalent in the cloud as they serve as the default
Linux / Endpoint Security
Cybersecurity researchers have disclosed two high-severity security flaws in the Ubuntu kernel that could pave the way for local privilege escalation attacks.
Cloud security firm Wiz, in a report shared with The Hacker News, said the easy-to-exploit shortcomings have the potential to impact 40% of Ubuntu users.
“The impacted Ubuntu versions are prevalent in the cloud as they serve as the default operating systems for multiple [cloud service providers],” security researchers Sagi Tzadik and Shir Tamari said.
The vulnerabilities – tracked as CVE-2023-32629 and 2023-2640 (CVSS scores: 7.8) and dubbed GameOver(lay) – are present in a module called OverlayFS and arise as a result of inadequate permissions checks in certain scenarios, enabling a local attacker to gain elevated privileges.
Overlay Filesystem refers to a union mount file system that makes it possible to combine multiple directory trees or file systems into a single, unified filesystem.
A brief description of the two flaws is below -
- CVE-2023-2640 - On Ubuntu kernels carrying both c914c0e27eb0 and “UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs,” an unprivileged user may set privileged extended attributes on the mounted files, leading them to be set on the upper files without the appropriate security checks.
- CVE-2023-32629 - Local privilege escalation vulnerability in Ubuntu Kernels overlayfs ovl_copy_up_meta_inode_data skip permission checks when calling ovl_do_setxattr on Ubuntu kernels
In a nutshell, GameOver(lay) makes it possible to "craft an executable file with scoped file capabilities and trick the Ubuntu Kernel into copying it to a different
UPCOMING WEBINAR
Shield Against Insider Threats: Master SaaS Security Posture Management
Worried about insider threats? We’ve got you covered! Join this webinar to explore practical strategies and the secrets of proactive security with SaaS Security Posture Management.
Join Today
location with unscoped capabilities, granting anyone who executes it root-like privileges."
Following responsible disclosure, the vulnerabilities have been fixed by Ubuntu as of July 24, 2023.
The findings underscore the fact that subtle changes in the Linux kernel introduced by Ubuntu could have unforeseen implications, Wiz CTO and co-founder Ami Luttwak said in a statement shared with the publication.
“Both vulnerabilities are unique to Ubuntu kernels since they stemmed from Ubuntu’s individual changes to the OverlayFS module,” the researchers said, adding the issues are comparable to other vulnerabilities such as CVE-2016-1576, CVE-2021-3493, CVE-2021-3847, and CVE-2023-0386.
Found this article interesting? Follow us on Twitter and LinkedIn to read more exclusive content we post.
Related news
It was discovered that the IP-VLAN network driver for the Linux kernel did not properly initialize memory in some situations, leading to an out-of- bounds write vulnerability. An attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. Querijn Voet discovered that a race condition existed in the io_uring subsystem in the Linux kernel, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. Various other vulnerabilities were also discovered and addressed.
Ubuntu Security Notice 6285-1 - It was discovered that the NTFS file system implementation in the Linux kernel did not properly check buffer indexes in certain situations, leading to an out-of-bounds read vulnerability. A local attacker could possibly use this to expose sensitive information. Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges.
Ubuntu Security Notice 6261-1 - It was discovered that the IP-VLAN network driver for the Linux kernel did not properly initialize memory in some situations, leading to an out-of- bounds write vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges.
Ubuntu Security Notice 6260-1 - It was discovered that the NTFS file system implementation in the Linux kernel did not properly check buffer indexes in certain situations, leading to an out-of-bounds read vulnerability. A local attacker could possibly use this to expose sensitive information. Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges.
Ubuntu Security Notice 6250-1 - Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges. It was discovered that the IP-VLAN network driver for the Linux kernel did not properly initialize memory in some situations, leading to an out-of- bounds write vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code.
Ubuntu Security Notice 6250-1 - Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges. It was discovered that the IP-VLAN network driver for the Linux kernel did not properly initialize memory in some situations, leading to an out-of- bounds write vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code.
Ubuntu Security Notice 6248-1 - It was discovered that the network queuing discipline implementation in the Linux kernel contained a null pointer dereference in some situations. A local attacker could use this to cause a denial of service. It was discovered that a race condition existed in Adreno GPU DRM driver in the Linux kernel, leading to a double-free vulnerability. A local attacker could use this to cause a denial of service.
Ubuntu Security Notice 6248-1 - It was discovered that the network queuing discipline implementation in the Linux kernel contained a null pointer dereference in some situations. A local attacker could use this to cause a denial of service. It was discovered that a race condition existed in Adreno GPU DRM driver in the Linux kernel, leading to a double-free vulnerability. A local attacker could use this to cause a denial of service.
Local privilege escalation vulnerability in Ubuntu Kernels overlayfs ovl_copy_up_meta_inode_data skip permission checks when calling ovl_do_setxattr on Ubuntu kernels
On Ubuntu kernels carrying both c914c0e27eb0 and "UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs", an unprivileged user may set privileged extended attributes on the mounted files, leading them to be set on the upper files without the appropriate security checks.
Red Hat Security Advisory 2023-1984-01 - This is a kernel live patch module which is automatically loaded by the RPM post-install script to modify the code of a running kernel.
An update for kpatch-patch is now available for Red Hat Enterprise Linux 9.0 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges o...
An update for kernel-rt is now available for Red Hat Enterprise Linux 9.0 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on t...
An update for kernel is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
An update for kernel-rt is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
An update for kpatch-patch is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
Red Hat Security Advisory 2023-1660-01 - This is a kernel live patch module which is automatically loaded by the RPM post-install script to modify the code of a running kernel.
An update for kpatch-patch is now available for Red Hat Enterprise Linux 8.6 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0266: A use-after-free flaw was found in snd_ctl_elem_read in sound/core/control.c in Advanced Linux Sound Architecture (ALSA) subsystem in the Linux kernel. In this flaw a normal privileged, local attacker may impact the system due to a locking issue in the compat path, leading to a kernel information leak problem. * CVE...
An update for kernel is now available for Red Hat Enterprise Linux 8.6 Extended Update Support. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original. Related CVEs: * CVE-2023-0266: A use-after-free flaw was found in the ALSA subsystem in sound/core/control.c in the Linux kernel. This flaw allows a local attacker to cause a use-after-free issue. * CVE-2023-0386: A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux...
A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.
Hello everyone! Great news for my open source Scanvus project! You can now perform vulnerability checks on Linux hosts and docker images not only using the Vulners.com API, but also with the Vulns.io VM API. It’s especially nice that all the code to support the new API was written and contributed by colleagues from Vulns.io. […]
By Deeba Ahmed The stealthy malware leverages security flaws to gain privilege escalation and establish persistence. This is a post from HackRead.com Read the original post: Stealthy Linux Malware Shikitega Deploying Monero Cryptominer
Categories: News Categories: Threats Researchers from the AT&T Alien Labs Resarch have discovered a stealthy new Linux malware. (Read more...) The post Evasive Shikitega Linux malware drops Monero cryptominer appeared first on Malwarebytes Labs.
The Shikitega malware takes over IoT and endpoint devices, exploits vulnerabilities, uses advanced encoding, abuses cloud services for C2, installs a cryptominer, and allows full remote control.
A new piece of stealthy Linux malware called Shikitega has been uncovered adopting a multi-stage infection chain to compromise endpoints and IoT devices and deposit additional payloads. "An attacker can gain full control of the system, in addition to the cryptocurrency miner that will be executed and set to persist," AT&T Alien Labs said in a new report published Tuesday. The findings add to a
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.