CWE-776

Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.

CVE-2025-3225 (GCVE-0-2025-3225)
Vulnerability from cvelistv5
Published
2025-07-07 09:54
Modified
2025-07-07 14:59
Severity ?
7.5 (High) - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-776 - Improper Restriction of Recursive Entity References in DTDs
Summary
An XML Entity Expansion vulnerability, also known as a 'billion laughs' attack, exists in the sitemap parser of the run-llama/llama_index repository, specifically affecting version v0.12.21. This vulnerability allows an attacker to supply a malicious Sitemap XML, leading to a Denial of Service (DoS) by exhausting system memory and potentially causing a system crash. The issue is resolved in version v0.12.29.
References
https://huntr.com/bounties/e33c0699-e9a2-49aa-837b-5363205637a2
https://github.com/run-llama/llama_index/commit/4f6ee062b19212106a2632af9c9521fc7f0a3584
Impacted products
Vendor Product Version
run-llama run-llama/llama_index Version: unspecified   < v0.12.29
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CVE-2025-5466 (GCVE-0-2025-5466)
Vulnerability from cvelistv5
Published
2025-08-12 15:00
Modified
2025-08-12 19:00
Severity ?
4.9 (Medium) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-776 - Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Summary
XEE in Ivanti Connect Secure before 22.7R2.8 or 22.8R2, Ivanti Policy Secure before 22.7R1.5, Ivanti ZTA Gateway before 22.8R2.3-723 and Ivanti Neurons for Secure Access before 22.8R1.4 (Fix deployed on 02-Aug-2025) allows a remote authenticated attacker with admin privileges to trigger a denial of service
References
https://forums.ivanti.com/s/article/August-Security-Advisory-Ivanti-Connect-Secure-Policy-Secure-ZTA-Gateways-Multiple-CVEs?language=en_US
Impacted products
Vendor Product Version
Ivanti Connect Secure Create a notification for this product.
   Ivanti Policy Secure Create a notification for this product.
   Ivanti ZTA Gateway Create a notification for this product.
   Ivanti Neurons for Secure Access Create a notification for this product.
Show details on NVD website

To clipboard 

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Mitigation

Phase: Operation

Description:

  • If possible, prohibit the use of DTDs or use an XML parser that limits the expansion of recursive DTD entities.
Mitigation

Phase: Implementation

Description:

  • Before parsing XML files with associated DTDs, scan for recursive entity declarations and do not continue parsing potentially explosive content.
CAPEC-197: Exponential Data Expansion

An adversary submits data to a target application which contains nested exponential data expansion to produce excessively large output. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.

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