CVE-2023-3823
Public on
Last Modified:
Insights vulnerability analysis
Description
A flaw was found in PHP due to inadequate validation of user-supplied XML input. By leveraging specially crafted XML code, a remote attacker could obtain sensitive information by viewing the contents of arbitrary files on the system or initiating requests to external systems. This issue may allow unauthorized access to sensitive data and the potential for network scanning of internal and external infrastructure.
Statement
Every application/library/server that is parsing/interacting with XML documents is affected.
Mitigation
To avoid XML external entity attacks, either disable external entity loading if it's not necessary for your application or change the default external entity loader by using `libxml_set_external_entity_loader`. This can be used to suppress the expansion of arbitrary external entities. For PHP versions prior to 8.0, the following should be set when using the default PHP XML parser in order to prevent XXE:
https://www.php.net/manual/en/function.libxml-set-external-entity-loader.php
Additional information
- Bugzilla 2229396: php: XML loading external entity without being enabled
- CWE-611: Improper Restriction of XML External Entity Reference
- FAQ: Frequently asked questions about CVE-2023-3823
External references
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
Red Hat | NVD | |
---|---|---|
CVSS v3 Base Score | 7.5 | 7.5 |
Attack Vector | Network | Network |
Attack Complexity | Low | Low |
Privileges Required | None | None |
User Interaction | None | None |
Scope | Unchanged | Unchanged |
Confidentiality Impact | High | High |
Integrity Impact | None | None |
Availability Impact | None | None |
CVSS v3 Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
What can I do if my product is listed as "Will not fix"?
What can I do if my product is listed as "Fix deferred"?
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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