Xen up to 4.11.x oxenstored resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

A vulnerability was found in Xen up to 4.11.x (Virtualization Software). It has been classified as critical. This affects an unknown code block of the component oxenstored. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. The summary by CVE is:

An issue was discovered in Xen through 4.11.x. The logic in oxenstored for handling writes depended on the order of evaluation of expressions making up a tuple. As indicated in section 7.7.3 "Operations on data structures" of the OCaml manual, the order of evaluation of subexpressions is not specified. In practice, different implementations behave differently. Thus, oxenstored may not enforce the configured quota-maxentity. This allows a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS.

The bug was discovered 08/14/2018. The weakness was shared 08/17/2018 by Jann Horn with Google Project Zero (Website). The advisory is shared at xenbits.xen.org. This vulnerability is uniquely identified as CVE-2018-15470 since 08/17/2018. An attack has to be approached locally. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 112158 (Xen Project Oxenstored Quota-maxentity DoS (XSA-272)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Misc. and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 171690 (SUSE Enterprise Linux Security Update for xen (SUSE-SU-2018:3490-1)).

Applying a patch is able to eliminate this problem. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (112158) and SecurityFocus (BID 103174†). The entries VDB-113918, VDB-117441, VDB-117508 and VDB-122910 are related to this item. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
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CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

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EPSS Percentile: 🔍

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Current Price Estimation: 🔍

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Nessus ID: 112158
Nessus Name: Xen Project Oxenstored Quota-maxentity DoS (XSA-272)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

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Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Timelineinfo

02/27/2018 🔍
08/14/2018 +168 days 🔍
08/14/2018 +0 days 🔍
08/17/2018 +2 days 🔍
08/17/2018 +0 days 🔍
08/17/2018 +0 days 🔍
08/18/2018 +1 days 🔍
08/28/2018 +10 days 🔍
05/02/2023 +1708 days 🔍

Sourcesinfo

Advisory: DLA 1577-1
Researcher: Jann Horn
Organization: Google Project Zero
Status: Confirmed

CVE: CVE-2018-15470 (🔍)
GCVE (CVE): GCVE-0-2018-15470
GCVE (VulDB): GCVE-100-123009
SecurityFocus: 103174 - Xen 'xen/common/memory.c' Denial of Service vulnerability

See also: 🔍

Entryinfo

Created: 08/18/2018 10:56 AM
Updated: 05/02/2023 01:58 PM
Changes: 08/18/2018 10:56 AM (71), 03/16/2020 03:06 PM (7), 05/02/2023 01:58 PM (4)
Complete: 🔍
Cache ID: 18:7E3:40

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