CyberSecBulletin
CVE-2023-40044Exploited in the wildNVD status: Analyzed

Progress WS_FTP Server Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2023-40044 is a high-severity deserialization of untrusted data vulnerability in WS_FTP Server from Progress Software, 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. The record lists versions 8.8.2, 8.7.4 as the first without the flaw, so updating WS_FTP Server to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on October 5, 2023, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update WS_FTP Server to 8.8.2 or 8.7.4, whichever matches your release line, or a later version.
  2. CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  3. Read the advisory on community.progress.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Progress SoftwareWS_FTP Server8.8.0 up to, but not including, 8.8.2; 8.7.0 up to, but not including, 8.7.48.8.2, 8.7.4

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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.110.0CriticalCNA (progress.com)
CVSS 3.18.8HighNVD

Official description

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

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

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other references

Other vulnerabilities in WS_FTP Server

All WS_FTP Server vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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