SolarWinds Web Help Desk (WHD) < 12.8.3 HF 1 - Remote Code Execution (RCE) via Java Deserialization Vulnerability (CVE-2024-28986)

Background & Context

SolarWinds Corporation is an American company that develops software for businesses to help manage their networks, systems, and information technology infrastructure. SolarWinds Web Help Desk (WHD) is an IT help desk software that centralizes, automates, and streamlines help desk management tasks. It is widely used by large corporations, government organizations, healthcare, education, and help desk centres.

Vulnerability Summary

A critical vulnerability exists in SolarWinds' Web Help Desk solution for customer support . The software was found to be susceptible to a Java Deserialization vulnerability. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions.

Impact If Exploited

When developers place no restrictions on "gadget chains," or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.

This could be exploited to achieve remote execution of arbitrary code (RCE). Exploit would allow an attacker to run commands on a vulnerable host machine.

NOTE: This vulnerability has NOT yet (as of 2024-08-15) been reported by the CISA (America's Cyber Defense Agency) under its 'KEV' (known exploited vulnerabilities') catalogue process to be known to be currently actively exploited in the wild. However the issue is sufficiently serious that Solarwinds have rushed out an urgent hotfix outside of normal security patch cycling, and which requires manual patching. SolarWinds is a popular platform and their 'Serv-U' solution has already been actively exploited earlier this year under CVE-2024-28995 so CVE-2024-28986 is considered highly likely to undergo active exploit by organised threat actors. Prioritisation should be given to remediation in any impacted environment.

Affected Product Versions

• SolarWinds Web Help Desk 12.8.3 and all previous versions , including WHD 12.4;WHD 12.5;WHD 12.6;WHD 12.7;WHD 12.8

Indicators of Compromise (IoC)

The vendor has not published a list of indicators of compromise (IoC) at the time of writing.

Official Fix & Remediation Guidance

The company has released a hotfix and recommends that all Web Help Desk customers apply the patch, which is now available. All versions of Web Help Desk (WHD) should be upgraded to WHD 12.8.3, and then the hotfix should be installed.

The hotfix is available here as a ZIP archive and requires Web Help Desk 12.8.3.1813. Admins have to manually add and modify specific files for the patch to work - SolarWinds has published a support article that provides complete instructions on how to apply the hotfix. SolarWinds recommends creating backup copies of the original files before replacing them, to avoid potential trouble in the case the hotfix was not applied correctly.

NOTE: Remediation of this vulnerability by patching to a specific version indicated may not be sufficient to secure the product against further vulnerabilities discovered in later versions, subsequent to the publication of this guidance. Unless contra-indicated, customers are therefore advised to always upgrade to the latest version of the product available.

Temporary Mitigation & Workarounds

(The vendor has not advised of any alternative temporary mitigation or workarounds)

NOTE: Caution should always be taken in applying any temporary mitigations listed. Mitigations are only recommended in cases where patches to remediate the vulnerability are not available, or cannot safely be applied to a given environment immediately. A given mitigation may not in all cases be recommended officially by the application vendor. The viability of any given temporary mitigation measure may vary, depending on server platform and existing configuration. Mitigations listed may incompletely remediate any given vulnerability. Configuration changes to implement listed mitigations may impact/disrupt required functionality within a given customer application. Care should therefore be taken to carefully analyse any listed mitigations for appropriateness to a given environment. Customers are advised to test any configuration changes prior to their being introduced into a production environment.

Vendor Advisories

• https://support.solarwinds.com/SuccessCenter/s/article/WHD-12-8-3-Hotfix-1

• https://www.solarwinds.com/trust-center/security-advisories/CVE-2024-28986

Third-Party Analysis & Threat Intelligence

• https://www.bleepingcomputer.com/news/security/solarwinds-fixes-critical-rce-bug-affecting-all-web-help-desk-versions/

PoC and Exploit Code

• TBC