XenSource Xen 4.3.x/4.4.x/4.5.x/4.6.x on x86 HVM Guest AMD PC-Net II Network Device hw/net/pcnet.c memory corruption

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8.7$0-$5k0.00

Summaryinfo

A vulnerability was found in XenSource Xen 4.3.x/4.4.x/4.5.x/4.6.x on x86 HVM Guest. It has been rated as critical. This affects an unknown part of the file hw/net/pcnet.c of the component AMD PC-Net II Network Device. This manipulation causes memory corruption. This vulnerability is registered as CVE-2015-7504. Remote exploitation of the attack is possible. No exploit is available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability classified as critical was found in XenSource Xen 4.3.x/4.4.x/4.5.x/4.6.x on x86 HVM Guest (Virtualization Software). Affected by this vulnerability is an unknown function of the file hw/net/pcnet.c of the component AMD PC-Net II Network Device. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Heap-based buffer overflow in the pcnet_receive function in hw/net/pcnet.c in QEMU allows guest OS administrators to cause a denial of service (instance crash) or possibly execute arbitrary code via a series of packets in loopback mode.

The weakness was published 11/30/2015 by Qinghao Tang with 360 Marvel Team as XSA-162 as confirmed security advisory (Website). The advisory is shared at xenbits.xen.org. This vulnerability is known as CVE-2015-7504 since 09/29/2015. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The advisory points out:

The AMD PC-Net II emulator(hw/net/pcnet.c), while receiving packets in loopback mode, appends CRC code to the receive buffer. If the data size given is same as the buffer size(4096), the appended CRC code overwrites 4 bytes after the s->buffer, making the adjacent 's->irq' object point to a new location.
The default configuration is not affected.

The vulnerability scanner Nessus provides a plugin with the ID 87604 (CentOS 6 : qemu-kvm (CESA-2015:2694)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CentOS Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 168296 (SUSE Enterprise Linux Security update for xen (SUSE-SU-2015:2306-1)).

Applying the patch xsa162-qemut.patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability. The security advisory contains the following remark:

Avoiding the use of emulated network devices altogether, by specifying a PV only VIF in the domain configuration file will avoid this issue. Avoiding the use of the PCNET device in favour of other emulations will also avoid this issue. Enabling stubdomains will mitigate this issue, by reducing the escalation to only those privileges accorded to the service domain. qemu-dm stubdomains are only available with the traditional "qemu-xen" version.

The vulnerability is also documented in the databases at Tenable (87604), SecurityFocus (BID 78227†), SecurityTracker (ID 1034268†) and Vulnerability Center (SBV-54694†). Similar entries are available at VDB-78958, VDB-79749 and VDB-80135. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Not Affected

  • XenSource Xen 4.3.x/4.4.x/4.5.x/4.6.x PV Guest

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.9
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.0
VulDB Temp Score: 8.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Memory corruption
CWE: CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 87604
Nessus Name: CentOS 6 : qemu-kvm (CESA-2015:2694)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703469
OpenVAS Name: Debian Security Advisory DSA 3469-1 (qemu - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Patch: xsa162-qemut.patch

Timelineinfo

09/29/2015 🔍
11/30/2015 +62 days 🔍
11/30/2015 +0 days 🔍
11/30/2015 +0 days 🔍
11/30/2015 +0 days 🔍
11/30/2015 +0 days 🔍
12/01/2015 +1 days 🔍
12/01/2015 +0 days 🔍
12/29/2015 +28 days 🔍
10/16/2017 +657 days 🔍
06/28/2022 +1716 days 🔍

Sourcesinfo

Vendor: citrix.com

Advisory: XSA-162
Researcher: Qinghao Tang
Organization: 360 Marvel Team
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2015-7504 (🔍)
GCVE (CVE): GCVE-0-2015-7504
GCVE (VulDB): GCVE-100-79345
SecurityFocus: 78227 - QEMU 'hw/net/pcnet.c' Heap Based Buffer Overflow Vulnerability
SecurityTracker: 1034268
Vulnerability Center: 54694 - QEMU Remote Code Execution due to Heap Based Buffer Overflow in \x27hw/net/pcnet.c\x27 Source File, Medium

See also: 🔍

Entryinfo

Created: 12/01/2015 09:51
Updated: 06/28/2022 08:33
Changes: 12/01/2015 09:51 (71), 05/09/2018 11:43 (19), 06/28/2022 08:33 (12)
Complete: 🔍
Cache ID: 216:A83:103

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