Linux Kernel up to 4.19 sas_expander.c smp_task_timedout/smp_task_done race condition
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
7.0 | $0-$5k | 0.00 |
A vulnerability classified as critical was found in Linux Kernel up to 4.19 (Operating System). This vulnerability affects the function smp_task_timedout/smp_task_done
in the library drivers/scsi/libsas/sas_expander.c. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:
An issue was discovered in the Linux kernel before 4.20. There is a race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c, leading to a use-after-free.
The weakness was disclosed 05/07/2019 (Website). The advisory is shared for download at access.redhat.com. This vulnerability was named CVE-2018-20836 since 05/07/2019. The attack can be initiated remotely. A single authentication is necessary for exploitation. There are known technical details, but no exploit is available.
The commercial vulnerability scanner Qualys is able to test this issue with plugin 157995 (Oracle Enterprise Linux Security Update for Unbreakable Enterprise kernel (ELSA-2019-4670)).
Upgrading to version 4.20 eliminates this vulnerability. The upgrade is hosted for download at git.kernel.org. The vulnerability will be addressed with the following lines of code:
del_timer(&task->slow_task->timer);
The entries 124429, 127125, 134460 and 134461 are pretty similar.
Product
Type
Vendor
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 7.2VulDB Meta Temp Score: 7.0
VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍
NVD Base Score: 8.1
NVD Vector: 🔍
CVSSv2
AV | AC | Au | C | I | A |
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💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
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Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
NVD Base Score: 🔍
Exploiting
Class: Race conditionCWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍
Local: No
Remote: Yes
Availability: 🔍
Status: Not defined
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
0-Day | unlock | unlock | unlock | unlock |
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Today | unlock | unlock | unlock | unlock |
Qualys ID: 🔍
Qualys Name: 🔍
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔍
Upgrade: Kernel 4.20
Patch: git.kernel.org
Timeline
09/24/2018 🔍05/07/2019 🔍
05/07/2019 🔍
05/08/2019 🔍
09/12/2023 🔍
Sources
Vendor: kernel.orgAdvisory: K11225249
Status: Confirmed
Confirmation: 🔍
CVE: CVE-2018-20836 (🔍)
SecurityFocus: 105388 - Linux Kernel 'chap_server_compute_md5()' Function Stack Buffer Overflow Vulnerability
See also: 🔍
Entry
Created: 05/08/2019 07:24Updated: 09/12/2023 20:28
Changes: 05/08/2019 07:24 (66), 06/08/2020 17:31 (3), 09/12/2023 20:21 (5), 09/12/2023 20:28 (1)
Complete: 🔍
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