CyberSecBulletin
CVE-2023-40595NVD status: Modified

Splunk Enterprise: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2023-40595 is a high-severity deserialization of untrusted data vulnerability in Splunk Enterprise from Splunk, 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 8.2.12, 9.0.6, 9.1.1 as the first without the flaw, so updating Splunk Enterprise to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.9% chance of exploitation within 30 days, higher than 60% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Splunk Enterprise to 8.2.12 or 9.0.6 or 9.1.1, whichever matches your release line, or a later version.
  2. Update Splunk Cloud to 9.0.2305.200 or a later version.
  3. Update Splunk to 8.2.12 or 9.0.6, whichever matches your release line, or a later version.
  4. Read the advisory on advisory.splunk.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
SplunkSplunk Enterprise8.2 up to, but not including, 8.2.12; 9.0 up to, but not including, 9.0.6; 9.1 up to, but not including, 9.1.18.2.12, 9.0.6, 9.1.1
SplunkSplunk Cloudbefore 9.0.2305.2009.0.2305.200
SplunkSplunk8.2.0 up to, but not including, 8.2.12; 9.0.0 up to, but not including, 9.0.6; 9.1.08.2.12, 9.0.6
SplunkSplunk Cloud Platform9.0.2305.100 and earlierNot 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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighCNA (splunk.com)
CVSS 3.18.8HighNVD

Official description

In Splunk Enterprise versions lower than 8.2.12, 9.0.6, and 9.1.1, an attacker can execute a specially crafted query that they can then use to serialize untrusted data. The attacker can use the query to execute arbitrary code.

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. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Splunk Enterprise

All Splunk Enterprise vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

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