SB2021020230 - Ubuntu update for linux-aws
Published: February 2, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Path traversal (CVE-ID: CVE-2020-28374)
The vulnerability allows a remote user to perform directory traversal attacks.
The vulnerability exists due to input validation error when processing directory traversal sequences in drivers/target/target_core_xcopy.c in the Linux kernel. A remote user with access to iSCSI LUN can send a specially crafted XCOPY request and read or write arbitrary files on the system.
2) Null pointer dereference (CVE-ID: CVE-2018-13093)
The vulnerability allows a local attacker to cause DoS condition on the target system.
The vulnerability exists in the lookup_slow() function in the Extended File System (XFS) component, as defined in the source code file fs/xfs/xfs_icache.c due to boundary error when mounting XFS filesystems. A local attacker can mount an XFS filesystem that submits malicious input, trigger NULL pointer dereference memory error and cause the affected software to terminate abnormally.
3) Use-after-free (CVE-ID: CVE-2019-19813)
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in __mutex_lock in kernel/locking/mutex.c. This is related to mutex_can_spin_on_owner in kernel/locking/mutex.c, __btrfs_qgroup_free_meta in fs/btrfs/qgroup.c, and btrfs_insert_delayed_items in fs/btrfs/delayed-inode.c.
4) Out-of-bounds write (CVE-ID: CVE-2019-19816)
The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.
In the Linux kernel 5.0.21, mounting a crafted btrfs filesystem image and performing some operations can cause slab-out-of-bounds write access in __btrfs_map_block in fs/btrfs/volumes.c, because a value of 1 for the number of data stripes is mishandled.
5) Use after free (CVE-ID: CVE-2020-25669)
The vulnerability allows a local user to execute arbitrary code.
A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed. Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still an alias in sunkbd_reinit causing Use After Free.
Remediation
Install update from vendor's website.