CVE-2019-8956 - Use After Free

Severity

72%

Complexity

39%

Confidentiality

165%

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.

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.

CVSS 3.0 Base Score 7.8. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 7.2. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:C/I:C/A:C).

Demo Examples

Use After Free

CWE-416

The following example demonstrates the weakness.


               
}
free(buf3R2);

Use After Free

CWE-416

The following code illustrates a use after free error:


               
}
free(ptr);
logError("operation aborted before commit", ptr);

When an error occurs, the pointer is immediately freed. However, this pointer is later incorrectly used in the logError function.

Overview

Type

Linux

First reported 5 years ago

2019-04-01 19:29:00

Last updated 5 years ago

2019-06-15 01:29:00

Affected Software

Linux Kernel

Canonical Ubuntu Linux 18.04 LTS Edition

18.04

Canonical Ubuntu Linux 18.10

18.10

References

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.21

Release Notes, Vendor Advisory

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.8

Release Notes, Vendor Advisory

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=ba59fb0273076637f0add4311faa990a5eec27c0

Mailing List, Patch, Vendor Advisory

https://secuniaresearch.flexerasoftware.com/secunia_research/2019-5/

Exploit, Third Party Advisory

https://support.f5.com/csp/article/K12671141

USN-3930-1

Third Party Advisory

USN-3930-2

Third Party Advisory

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