CyberSecBulletin
CVE-2022-36969NVD status: Modified

Edge: Improper Restriction of XML External Entity Reference

Published Updated By the CyberSecBulletin desk

CVE-2022-36969 is a high-severity improper restriction of XML external entity reference vulnerability in Edge from AVEVA, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected Edge versions: 2020 SP2 Patch 0(4201.2111.1802.0000). The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 13.7% chance of exploitation within 30 days, which is in the top 3.45% of all scored CVEs.

Patch this week

EPSS places it among the vulnerabilities most likely to be exploited soon.

What to do

  1. Update Aveva Edge to 2020.2.00.40 or a later version.
  2. Read the advisory on aveva.com for workarounds and exact fixed builds.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
AVEVAEdge2020 SP2 Patch 0(4201.2111.1802.0000)Not stated
AvevaAveva Edgebefore 2020.2.00.402020.2.00.40

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.1HighNVD
CVSS 3.05.5MediumCNA (trendmicro.com)

Official description

This vulnerability allows remote attackers to disclose sensitive information on affected installations of AVEVA Edge 2020 SP2 Patch 0(4201.2111.1802.0000). User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the LoadImportedLibraries method. Due to the improper restriction of XML External Entity (XXE) references, a crafted document specifying a URI causes the XML parser to access the URI and embed the contents back into the XML document for further processing. An attacker can leverage this vulnerability to disclose information in the context of the current process. Was ZDI-CAN-17394.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

How developers prevent this class of flaw

  • Many XML parsers and validators can be configured to disable external entity expansion.

More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Edge

All Edge vulnerabilities

Recent Improper Restriction of XML External Entity Reference vulnerabilities

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