Linux Kernel up to 4.19.20/4.20.7 net/sctp/socket.c sctp_sendmsg use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 4.19.20/4.20.7. It has been classified as critical. This issue affects the function sctp_sendmsg of the file net/sctp/socket.c. This manipulation causes use after free. This vulnerability is tracked as CVE-2019-8956. The attack is restricted to local execution. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 4.19.20/4.20.7 (Operating System). Affected by this vulnerability is the function sctp_sendmsg of the file net/sctp/socket.c. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux Kernel before versions 4.20.8 and 4.19.21 a use-after-free error in the "sctp_sendmsg()" function (net/sctp/socket.c) when handling SCTP_SENDALL flag can be exploited to corrupt memory.

The bug was discovered 02/21/2019. The weakness was disclosed 04/01/2019 by Felix Wilhelm (Website). The advisory is shared at usn.ubuntu.com. This vulnerability is known as CVE-2019-8956 since 02/20/2019. The exploitation appears to be easy. An attack has to be approached locally. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 39 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 197413 (Ubuntu Security Notification for Linux, Linux-aws, Linux-azure, Linux-gcp, Linux-kvm, Linux-raspi2 (USN-3930-1)).

Upgrading to version 4.19.21 or 4.20.8 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 106963†). The entries VDB-120204, VDB-127742, VDB-131104 and VDB-131213 are pretty similar. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.19.21/4.20.8
Patch: git.kernel.org

Timelineinfo

02/07/2019 🔍
02/20/2019 +13 days 🔍
02/21/2019 +1 days 🔍
04/01/2019 +39 days 🔍
04/02/2019 +1 days 🔍
08/21/2023 +1602 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: K12671141
Researcher: Felix Wilhelm
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2019-8956 (🔍)
GCVE (CVE): GCVE-0-2019-8956
GCVE (VulDB): GCVE-100-132697
SecurityFocus: 106963 - Linux Kernel CVE-2019-7222 Local Information Disclosure Vulnerability

See also: 🔍

Entryinfo

Created: 04/02/2019 08:16
Updated: 08/21/2023 11:43
Changes: 04/02/2019 08:16 (64), 05/23/2020 16:45 (6), 08/21/2023 11:36 (5), 08/21/2023 11:43 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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