CyberSecBulletin
CVE-2023-1109NVD status: Modified

ENERGY AXC PU (1264327): Improper Limitation of a Pathname to a Restricted Directory

CVE-2023-1109 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in ENERGY AXC PU (1264327) from Phoenix Contact, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected ENERGY AXC PU (1264327) versions: V01.00.00.00 through V04.15.00.00. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.76% chance of exploitation within 30 days, higher than 56% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of ENERGY AXC PU (1264327) you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
PHOENIX CONTACTENERGY AXC PU (1264327)V01.00.00.00 through V04.15.00.00Not stated
PHOENIX CONTACTSMARTRTU AXC SG (1110435)V01.00.00.00 through V01.08.00.02Not stated
PHOENIX CONTACTSMARTRTU AXC IG (1264328)V01.00.00.00 through V01.02.00.01Not stated
PHOENIX CONTACTInfobox (1169323 )V01.00.00.00 through V02.02.00.00Not stated
PhoenixcontactEnergy Axc Pu01.00.00.00 through 04.15.00.00Not stated
PhoenixcontactInfobox Firmware01.00.00.00 through 02.02.00.00Not stated
PhoenixcontactSmartrtu Axc Sg Firmware01.00.00.00 through 01.08.00.02Not stated
PhoenixcontactSmartrtu Axc Ig Firmware01.00.00.00 through 01.02.00.01Not 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
LowA basic user account is enough.
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
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cert.vde.com).

Official description

In Phoenix Contacts ENERGY AXC PU Web service an authenticated restricted user of the web frontend can access, read, write and create files throughout the file system using specially crafted URLs via the upload and download functionality of the web service. This may lead to full control of the service.

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

The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)

Timeline

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

References

Advisories

Other references

Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities

Spotted an error? Tell us.