SB20200903129 - Ubuntu update for linux
Published: September 3, 2020 Updated: April 23, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 13 secuirty vulnerabilities.
1) Privilege escalation (CVE-ID: CVE-2018-20669)
The vulnerability allows a local attacker to escalate privileges on the system.
The vulnerability exists in i915_gem_execbuffer2_ioctl in drivers/gpu/drm/i915/i915_gem_execbuffer.c due to a provided address with access_ok() is not checked before accessing userspace data in certain situations. A local attacker can gain elevated privileges.
2) Use of uninitialized resource (CVE-ID: CVE-2019-19947)
The vulnerability allows a local non-authenticated attacker to gain access to sensitive information.
In the Linux kernel through 5.4.6, there are information leaks of uninitialized memory to a USB device in the drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c driver, aka CID-da2311a6385c.
3) Input validation error (CVE-ID: CVE-2019-20810)
The vulnerability allows a local authenticated user to perform a denial of service (DoS) attack.
go7007_snd_init in drivers/media/usb/go7007/snd-go7007.c in the Linux kernel before 5.6 does not call snd_card_free for a failure path, which causes a memory leak, aka CID-9453264ef586.
4) Use of uninitialized resource (CVE-ID: CVE-2020-10732)
The vulnerability allows a local user to read memory contents or crash the application.
The vulnerability exists due to use of uninitialized resource error within the fill_thread_core_info() function in fs/binfmt_elf.c. A local user can read memory contents or crash the application.
5) Race condition (CVE-ID: CVE-2020-10766)
The vulnerability allows a local user to gain access to sensitive information.
A logic bug flaw was found in Linux kernel before 5.8-rc1 in the
implementation of SSBD. A bug in the logic handling allows an attacker
with a local account to disable SSBD protection during a context switch
when additional speculative execution mitigations are in place. This
issue was introduced when the per task/process conditional STIPB
switching was added on top of the existing SSBD switching.
6) Resource management error (CVE-ID: CVE-2020-10767)
The vulnerability allows a local user to gain access to sensitive information.
A flaw was found in the Linux kernel before 5.8-rc1 in the
implementation of the Enhanced IBPB (Indirect Branch Prediction
Barrier). The IBPB mitigation will be disabled when STIBP is not
available or when the Enhanced Indirect Branch Restricted Speculation
(IBRS) is available. This flaw allows a local user to perform a Spectre
V2 style attack when this configuration is active.
7) Input validation error (CVE-ID: CVE-2020-10768)
The vulnerability allows a local authenticated user to gain access to sensitive information.
A flaw was found in the Linux Kernel before 5.8-rc1 in the prctl() function, where it can be used to enable indirect branch speculation after it has been disabled. This call incorrectly reports it as being 'force disabled' when it is not and opens the system to Spectre v2 attacks. The highest threat from this vulnerability is to confidentiality.
8) Resource exhaustion (CVE-ID: CVE-2020-10781)
The vulnerability allows a local authenticated user to perform a denial of service (DoS) attack.
A flaw was found in the Linux Kernel before 5.8-rc6 in the ZRAM kernel module, where a user with a local account and the ability to read the /sys/class/zram-control/hot_add file can create ZRAM device nodes in the /dev/ directory. This read allocates kernel memory and is not accounted for a user that triggers the creation of that ZRAM device. With this vulnerability, continually reading the device may consume a large amount of system memory and cause the Out-of-Memory (OOM) killer to activate and terminate random userspace processes, possibly making the system inoperable.
9) Resource exhaustion (CVE-ID: CVE-2020-12655)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources in "xfs_agf_verify" in "fs/xfs/libxfs/xfs_alloc.c" file. A local user can use an XFS v5 image with crafted metadata, trigger resource exhaustion and perform a denial of service (DoS) attack.
10) Input validation error (CVE-ID: CVE-2020-12771)
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a deadlock if a coalescing operation fails in "btree_gc_coalesce" in "drivers/md/bcache/btree.c" file. A local user can pass specially crafted input to the application and perform a denial of service (DoS) attack.
11) Integer overflow (CVE-ID: CVE-2020-13974)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to integer overflow within drivers/tty/vt/keyboard.c if k_ascii is called several times in a row. A local user can trigger an integer overflow and execute arbitrary code with elevated privileges.
12) Memory leak (CVE-ID: CVE-2020-15393)
The vulnerability allows a local user to perform DoS attack on the target system.
The vulnerability exists due memory leak in "drivers/usb/misc/usbtest.c" file. A local user can force the application to leak memory and perform denial of service attack.
13) Incorrect permission assignment for critical resource (CVE-ID: CVE-2020-24394)
The vulnerability allows a local user to bypass implemented security restrictions.
The vulnerability exists due to incorrect assignment of permissions on new filesystem objects when the filesystem lacks ACL support in fs/nfsd/vfs.c (in the NFS server). A local user can read and write arbitrary files on the system.
Remediation
Install update from vendor's website.