A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-414646 advisory.

    A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions     in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race     conditions were implicitly introduced in the commits that added VSOCK multi-transport support.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions     in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race     conditions were implicitly introduced in the commits that added VSOCK multi-transport support.
    (CVE-2021-26708)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote AlmaLinux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2021:1093 advisory.

  - In do_epoll_ctl and ep_loop_check_proc of eventpoll.c, there is a possible use after free due to a logic     error. This could lead to local escalation of privilege with no additional execution privileges needed.
    User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID:
    A-147802478References: Upstream kernel (CVE-2020-0466)

  - An issue was discovered in ioapic_lazy_update_eoi in arch/x86/kvm/ioapic.c in the Linux kernel before     5.9.2. It has an infinite loop related to improper interaction between a resampler and edge triggering,     aka CID-77377064c3a9. (CVE-2020-27152)

  - In drivers/target/target_core_xcopy.c in the Linux kernel before 5.10.7, insufficient identifier checking     in the LIO SCSI target code can be used by remote attackers to read or write files via directory traversal     in an XCOPY request, aka CID-2896c93811e3. For example, an attack can occur over a network if the attacker     has access to one iSCSI LUN. The attacker gains control over file access because I/O operations are     proxied via an attacker-selected backstore. (CVE-2020-28374)

  - An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free     during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.
    (CVE-2021-3347)

  - A local privilege escalation was discovered in the Linux kernel before 5.10.13. Multiple race conditions     in the AF_VSOCK implementation are caused by wrong locking in net/vmw_vsock/af_vsock.c. The race     conditions were implicitly introduced in the commits that added VSOCK multi-transport support.
    (CVE-2021-26708)

  - An issue was discovered in the Linux kernel through 5.11.3. A kernel pointer leak can be used to determine     the address of the iscsi_transport structure. When an iSCSI transport is registered with the iSCSI     subsystem, the transport's handle is available to unprivileged users via the sysfs file system, at     /sys/class/iscsi_transport/$TRANSPORT_NAME/handle. When read, the show_transport_handle function (in     drivers/scsi/scsi_transport_iscsi.c) is called, which leaks the handle. This handle is actually the     pointer to an iscsi_transport struct in the kernel module's global variables. (CVE-2021-27363)

  - An issue was discovered in the Linux kernel through 5.11.3. drivers/scsi/scsi_transport_iscsi.c is     adversely affected by the ability of an unprivileged user to craft Netlink messages. (CVE-2021-27364)

  - An issue was discovered in the Linux kernel through 5.11.3. Certain iSCSI data structures do not have     appropriate length constraints or checks, and can exceed the PAGE_SIZE value. An unprivileged user can     send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a     Netlink message. (CVE-2021-27365)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the CESA-2021:1093 advisory.

  - kernel: use after free in eventpoll.c may lead to escalation of privilege (CVE-2020-0466)

  - Kernel: KVM: host stack overflow due to lazy update IOAPIC (CVE-2020-27152)

  - kernel: SCSI target (LIO) write to any block on ILO backstore (CVE-2020-28374)

  - kernel: race conditions caused by wrong locking in net/vmw_vsock/af_vsock.c (CVE-2021-26708)

  - kernel: iscsi: unrestricted access to sessions and handles (CVE-2021-27363)

  - kernel: out-of-bounds read in libiscsi module (CVE-2021-27364)

  - kernel: heap buffer overflow in the iSCSI subsystem (CVE-2021-27365)

  - kernel: Use after free via PI futex state (CVE-2021-3347)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2021-1093 advisory.

    - futex: Handle faults correctly for PI futexes (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Simplify fixup_pi_state_owner() (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Use pi_state_update_owner() in put_pi_state() (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Provide and use pi_state_update_owner() (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - rtmutex: Remove unused argument from rt_mutex_proxy_unlock() (Waiman Long) [1924633 1924635]     {CVE-2021-3347}
    - futex: Replace pointless printk in fixup_owner() (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Ensure the correct return value from futex_lock_pi() (Waiman Long) [1924633 1924635]     {CVE-2021-3347}
    - futex: Don't enable IRQs unconditionally in put_pi_state() (Waiman Long) [1924633 1924635]     {CVE-2021-3347}
    - futex: Fix incorrect should_fail_futex() handling (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Consistently use fshared as boolean (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Remove needless goto's (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - futex: Remove put_futex_key() (Waiman Long) [1924633 1924635] {CVE-2021-3347}
    - scsi: iscsi: Verify lengths on passthrough PDUs (Chris Leech) [1930832 1930833] {CVE-2021-27364}
    - scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE (Chris Leech) [1930855 1930856]     {CVE-2021-27365}
    - scsi: iscsi: Restrict sessions and handles to admin capabilities (Chris Leech) [1940423 1930809]     {CVE-2021-27363}
    - fix regression in 'epoll: Keep a reference on files added to the check list' (Carlos Maiolino) [1920775     1920776] {CVE-2020-0466}
    - do_epoll_ctl(): clean the failure exits up a bit (Carlos Maiolino) [1920775 1920776] {CVE-2020-0466}
    - epoll: Keep a reference on files added to the check list (Carlos Maiolino) [1920775 1920776]     {CVE-2020-0466}
    - net/vmw_vsock: fix NULL pointer dereference (Jon Maloy) [1925599 1925600] {CVE-2021-26708}
    - net/vmw_vsock: improve locking in vsock_connect_timeout() (Jon Maloy) [1925599 1925600] {CVE-2021-26708}
    - vsock: fix locking in vsock_shutdown() (Jon Maloy) [1925599 1925600] {CVE-2021-26708}
    - vsock: fix the race conditions in multi-transport support (Jon Maloy) [1925599 1925600] {CVE-2021-26708}
    - [target] scsi: target: Fix XCOPY NAA identifier lookup (Maurizio Lombardi) [1900462 1900463]     {CVE-2020-28374}

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:1093 advisory.

    The kernel packages contain the Linux kernel, the core of any Linux operating system.

    Security Fix(es):

    * kernel: use after free in eventpoll.c may lead to escalation of privilege (CVE-2020-0466)

    * kernel: SCSI target (LIO) write to any block on ILO backstore (CVE-2020-28374)

    * kernel: Use after free via PI futex state (CVE-2021-3347)

    * kernel: race conditions caused by wrong locking in net/vmw_vsock/af_vsock.c (CVE-2021-26708)

    * kernel: out-of-bounds read in libiscsi module (CVE-2021-27364)

    * kernel: heap buffer overflow in the iSCSI subsystem (CVE-2021-27365)

    * Kernel: KVM: host stack overflow due to lazy update IOAPIC (CVE-2020-27152)

    * kernel: iscsi: unrestricted access to sessions and handles (CVE-2021-27363)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Bug Fix(es):

    * race condition when creating child sockets from syncookies (BZ#1915529)

    * On System Z, a hash needs state randomized for entropy extraction (BZ#1915816)

    * scsi: target: core_tmr_abort_task() reporting multiple aborts for the same se_cmd->tag (BZ#1918354)

    * [mlx5] VF interface stats are not reflected in ip -s link show / ifconfig <vf> commands (BZ#1921060)

    * Win10 guest automatic reboot after migration in Win10 and WSL2 on Intel hosts (BZ#1923281)

    * [RHEL 8.3] Repeated messages - Unable to burst-read optrom segment (BZ#1924222)

    * Backport bug fix RDMA/umem: Prevent small pages from being returned by ib_umem_find_best_pgsz     (BZ#1924691)

    * [Cisco 8.3] RHEL/Cent 8.2 fNIC driver needs a patch fix that addresses crash (BZ#1925186)

    * RHEL8.3 - The kernel misdetects zCX with z/VM (BZ#1925508)

    * Backport 22e4663e91 (mm/slub: fix panic in slab_alloc_node()) (BZ#1925511)

    * SCTP Address already in use when no active endpoints from RHEL 8.2 onwards (BZ#1927521)

    * lpfc: Fix initial FLOGI failure due to BBSCN not supported  (BZ#1927921)

    * [mm] mm, oom: remove oom_lock from oom_reaper (BZ#1929738)

    * Unexpected thread movement with AMD Milan compared to Rome (BZ#1929740)

    * rpmbuild cannot build the userspace RPMs in the kernel package when the kernel itself is not built     (BZ#1929910)

    * [Regression] RHEL8.2 - ISST-LTE:pVM:diapvmlp83:sum:memory DLPAR fails to add memory on multiple     trials[mm/memory_hotplug.c:1163] (mm-) (BZ#1930168)

    * Configuring the system with non-RT kernel will hang the system (BZ#1930735)

    * Upstream Patch for Gracefully handle DMAR units with no supported address widthsx86/vt-d (BZ#1932199)

    * gfs2: Deadlock between gfs2_{create_inode,inode_lookup} and delete_work_func (BZ#1937109)

    * Failing on tsx-ctrl when the flag doesn't change anything (BZ#1939013)

    Enhancement(s):

    * RFE: Backport all Audit enhancements and fixes up to version 5.10-rc1 (BZ#1907520)

    * RHEL8.4: Update the target driver (BZ#1918363)

    * [Mellanox 8.4 FEAT] mlx5: Hairpin Support in Switch Mode (BZ#1924689)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:1081 advisory.

    The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with     extremely high determinism requirements.

    Security Fix(es):

    * kernel: use after free in eventpoll.c may lead to escalation of privilege (CVE-2020-0466)

    * kernel: SCSI target (LIO) write to any block on ILO backstore (CVE-2020-28374)

    * kernel: Use after free via PI futex state (CVE-2021-3347)

    * kernel: race conditions caused by wrong locking in net/vmw_vsock/af_vsock.c (CVE-2021-26708)

    * kernel: out-of-bounds read in libiscsi module (CVE-2021-27364)

    * kernel: heap buffer overflow in the iSCSI subsystem (CVE-2021-27365)

    * Kernel: KVM: host stack overflow due to lazy update IOAPIC (CVE-2020-27152)

    * kernel: iscsi: unrestricted access to sessions and handles (CVE-2021-27363)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Bug Fix(es):

    * kernel-rt possible livelock: WARNING: CPU: 28 PID: 3109 at kernel/ptrace.c:242     ptrace_check_attach+0xdd/0x1a0 (BZ#1925308)

    * kernel-rt: update RT source tree to the RHEL-8.3.z3 source tree (BZ#1926369)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the linux package has been released.

The remote Ubuntu 20.04 LTS host has a package installed that is affected by a vulnerability as referenced in the USN-4727-1 advisory.

    Alexander Popov discovered that multiple race conditions existed in the AF_VSOCK implementation in the     Linux kernel. A local attacker could use this to cause a denial of service (system crash) or execute     arbitrary code.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
267522	Unity Linux 20.1070e Security Update: kernel (UTSA-2025-414646)	Nessus	Unity Linux Local Security Checks	high
247696	Linux Distros Unpatched Vulnerability : CVE-2021-26708	Nessus	Misc.	high
157559	AlmaLinux 8 : kernel (ALSA-2021:1093)	Nessus	Alma Linux Local Security Checks	high
148422	CentOS 8 : kernel (CESA-2021:1093)	Nessus	CentOS Local Security Checks	high
148371	Oracle Linux 8 : kernel (ELSA-2021-1093)	Nessus	Oracle Linux Local Security Checks	high
148370	RHEL 8 : kernel (RHSA-2021:1093)	Nessus	Red Hat Local Security Checks	high
148369	RHEL 8 : kernel-rt (RHSA-2021:1081)	Nessus	Red Hat Local Security Checks	high
148350	Photon OS 4.0: Linux PHSA-2021-4.0-0007	Nessus	PhotonOS Local Security Checks	high
146350	Ubuntu 20.04 LTS : Linux kernel vulnerability (USN-4727-1)	Nessus	Ubuntu Local Security Checks	high

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CVE-2021-26708

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