CVE-2016-6833 - Use After Free

Severity

21%

Complexity

39%

Confidentiality

48%

Use-after-free vulnerability in the vmxnet3_io_bar0_write function in hw/net/vmxnet3.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU instance crash) by leveraging failure to check if the device is active.

Use-after-free vulnerability in the vmxnet3_io_bar0_write function in hw/net/vmxnet3.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (QEMU instance crash) by leveraging failure to check if the device is active.

CVSS 3.0 Base Score 4.4. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

CVSS 2.0 Base Score 2.1. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:N/I:N/A:P).

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

First reported 8 years ago

2016-12-10 00:59:00

Last updated 6 years ago

2018-09-07 10:29:00

Affected Software

QEMU

References

http://git.qemu.org/?p=qemu.git;a=commit;h=6c352ca9b4ee3e1e286ea9e8434bd8e69ac7d0d8

Issue Tracking, Patch

[oss-security] 20160812 CVE request: Qemu net: vmxnet3: use after free while writing

Mailing List, Third Party Advisory

[oss-security] 20160817 Re: CVE request: Qemu net: vmxnet3: use after free while writing

Mailing List, Third Party Advisory

93255

Third Party Advisory, VDB Entry

[debian-lts-announce] 20180906 [SECURITY] [DLA 1497-1] qemu security update

[qemu-devel] 20160809 [PULL 2/3] net: vmxnet3: check for device_active before write

Patch, Vendor Advisory

GLSA-201609-01

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