CyberSecBulletin
CVE-2024-34581NVD status: Deferred

xml_signature_syntax_and_processing: Server-Side Request Forgery

Published Updated By the CyberSecBulletin desk

CVE-2024-34581 is a high-severity server-side request forgery vulnerability in xml_signature_syntax_and_processing from W3c, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 1.1, 2.0 as the first without the flaw, so updating xml_signature_syntax_and_processing to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.25% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update xml_signature_syntax_and_processing to 1.1 or 2.0, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
W3cxml_signature_syntax_and_processingbefore 1.1; before 2.01.1, 2.0

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
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CISA (ADP).

Official description

The W3C XML Signature Syntax and Processing (XMLDsig) specification, starting with 1.0, was originally published with a "RetrievalMethod is a URI ... that may be used to obtain key and/or certificate information" statement and no accompanying information about SSRF risks, and this may have contributed to vulnerable implementations such as those discussed in CVE-2023-36661 and CVE-2024-21893. NOTE: this was mitigated in 1.1 and 2.0 via a directly referenced Best Practices document that calls on implementers to be wary of SSRF.

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

The underlying weakness: Server-Side Request Forgery

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

How developers prevent this class of flaw

  • If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
  • If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.

More Server-Side Request Forgery vulnerabilities (CWE-918)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Server-Side Request Forgery vulnerabilities

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