Now Platform: Improper Control of Generation of Code
CVE-2024-8923 is a critical-severity improper control of generation of code vulnerability in Now Platform from ServiceNow, with a CVSS 3.1 base score of 10.0 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 Vancouver Patch 9 Hot Fix 2a, Vancouver Patch 10, Washington DC Patch 4 Hot Fix 1a as the first without the flaw, so updating Now Platform to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.11% chance of exploitation within 30 days, higher than 66% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Now Platform to Vancouver Patch 9 Hot Fix 2a or Vancouver Patch 10 or Washington DC Patch 4 Hot Fix 1a or Washington DC Patch 5, whichever matches your release line, or a later version.
- Update servicenow to Vancouver Patch 9 Hot Fix 2a or Vancouver Patch 10 or Washington DC Patch 4 Hot Fix 1a or Washington DC Patch 5, whichever matches your release line, or a later version.
- Read the advisory on support.servicenow.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| ServiceNow | Now Platform | before Vancouver Patch 9 Hot Fix 2a; before Vancouver Patch 10; before Washington DC Patch 4 Hot Fix 1a; before Washington DC Patch 5; before Xanadu GA Release | Vancouver Patch 9 Hot Fix 2a, Vancouver Patch 10, Washington DC Patch 4 Hot Fix 1a, Washington DC Patch 5, Xanadu GA Release |
| Servicenow | servicenow | Vancouver up to, but not including, Vancouver Patch 9 Hot Fix 2a; Vancouver up to, but not including, Vancouver Patch 10; Washington_DC up to, but not including, Washington DC Patch 4 Hot Fix 1a; Washington_DC up to, but not including, Washington DC Patch 5; Xanadu up to, but not including, Xanadu GA Release | Vancouver Patch 9 Hot Fix 2a, Vancouver Patch 10, Washington DC Patch 4 Hot Fix 1a, Washington DC Patch 5, Xanadu GA Release |
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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:N/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (servicenow.com) |
| CVSS 3.1 | 9.8 | Critical | CNA (servicenow.com) |
| CVSS 3.1 | 10.0 | Critical | NVD |
Official description
ServiceNow has addressed an input validation vulnerability that was identified in the Now Platform. This vulnerability could enable an unauthenticated user to remotely execute code within the context of the Now Platform. ServiceNow deployed an update to hosted instances and ServiceNow provided the update to our partners and self-hosted customers. Further, the vulnerability is addressed in the listed patches and hot fixes.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Now Platform
- 8.2 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
ServiceNow Improper Input Validation Exploited
Recent Improper Control of Generation of Code vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
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