North Grid Proself Improper Restriction of XML External Entity (XXE) Reference
CVE-2023-45727 is a high-severity improper restriction of XML external entity reference vulnerability in Proself Enterprise/Standard Edition from North Grid, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Proself Enterprise/Standard Edition versions: Ver5.62 and earlier. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on December 3, 2024, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Proself Enterprise/Standard Edition you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Read the advisory on proself.jp for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| North Grid | Proself Enterprise/Standard Edition | Ver5.62 and earlier | Not stated |
| North Grid | Proself Gateway Edition | Ver1.65 and earlier | Not stated |
| North Grid | Proself Mail Sanitize Edition | Ver1.08 and earlier | Not stated |
| Northgrid | proself | 5.62 and earlier; 1.65 and earlier; 1.08 and earlier | Not stated |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
Proself Enterprise/Standard Edition Ver5.62 and earlier, Proself Gateway Edition Ver1.65 and earlier, and Proself Mail Sanitize Edition Ver1.08 and earlier allow a remote unauthenticated attacker to conduct XML External Entity (XXE) attacks. By processing a specially crafted request containing malformed XML data, arbitrary files on the server containing account information may be read by the attacker.
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
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: partial).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- jvn.jp/en/jp/JVN95981460/Third Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-45727US Government Resource
Other vulnerabilities in Proself Enterprise/Standard Edition
- 7.2 High severity
- 7.5 High severity
Recent Improper Restriction of XML External Entity Reference vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 7.4 High severity
- 8.8 High severity
- 9.1 Critical severity
- 7.5 High severity
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