Citrix ShareFile vulnerability actively exploited (CVE-2023-24489)
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2023-24489 | Unauthenticated RCE in Citrix ShareFile Storage Zones Controller (CVE-2023-24489) CVE-2023-24489 is an improper access control flaw (CWE-284), rated critical at CVSS 9.8, in the customer-managed Citrix Content Collaboration ShareFile storage zones controller. It can be triggered remotely over the network by an unauthenticated attacker with no privileges and no user interaction (AV:N/AC:L/PR:N/UI:N). A successful attack allows the attacker to remotely compromise the customer-managed storage zones controller — described in vendor-adjacent coverage as remote code execution — giving control of the server that stores and syncs that organization's ShareFile files. Only organizations that self-host customer-managed storage zones controllers are affected; the vendor-managed (cloud) ShareFile service is not listed as affected. The flaw is being actively exploited in the wild: CISA added it to the KEV catalog on 2023-08-16, EPSS assigns a 97.3% probability of exploitation within 30 days (100th percentile), and the vendor urged customers to shut down or take unpatched controllers offline; ransomware use is not yet confirmed. Do: Apply the fix specified in the Citrix/ShareFile security bulletin by upgrading every customer-managed storage zones controller to the vendor's patched release, and follow vendor guidance to shut down or take offline any controller that cannot be patched immediately. Check whether controllers are internet-exposed and hunt for signs of compromise (unexpected files, processes, or webshells on storage zones), since the flaw is in the KEV catalog and ransomware use has not been ruled out. | 9.8 | 97% | KEV |
| moderate≈ thousands of internet-exposed customer-managed storage zone controllers (order-of-magnitude estimate) |
Full article389 words · extracted from helpnetsecurity.com · click to collapse
CVE-2023-24489, a critical Citrix ShareFile vulnerability that the company has fixed in June 2023, is being exploited by attackers.
GreyNoise has flagged on Tuesday a sudden spike in IP addresses from which exploitation attempts are coming, and the Cybersecurity and Infrastructure Agency (CISA) has added the vulnerability to its Known Exploited Vulnerabilities Catalog.
About CVE-2023-24489
Unearthed and reported by Assetnote researcher Dylan Pindur, CVE-2023-24489 affects the popular cloud-based file-sharing application Citrix ShareFile, more specifically its storage zones controller (a .NET web application running under IIS).
“You can use the ShareFile-managed cloud storage by itself or in combination with storage that you maintain, called storage zones for ShareFile Data. The storage zones that you maintain can reside in your on-premises single-tenant storage system or in supported third-party cloud storage,” Citrix explains.
Storage zones controller allows users to securely access SharePoint sites and network file shares through storage zone connectors, which enable ShareFile client users to browse, upload, or download documents.
In essence, CVE-2023-24489 is a cryptographic bug that may allow unauthenticated attackers to upload files and (ultimately) execute code on and compromise a vulnerable customer-managed installation.
CVE-2023-24489 has been fixed in ShareFile storage zones controller v5.11.24 and later, and customers have been urged to upgrade ever since.
Why is CVE-2023-24489 being exploited now?
Vulnerabilities in enterprise-grade file-sharing applications are often exploited by attackers, especially the Cl0p cyber extortion gang, who previously targeted organizations using Accellion File Transfer Appliance (FTA) devices, the GoAnywhere MFT platform, and the MOVEit Transfer solution.
The existence of CVE-2023-24489 and of the fix has been publicly revealed in June 2023, but it wasn’t until July 4 that Assetnote published additional technical details and a proof-of-concept (PoC) exploit. Other PoCs have been released on GitHub since then, so it was just a matter of time until attackers used them to create working exploits and leverage them.
According to GreyNoise’s online tracker of exploit activity related to this vulnerability, first signs have been registered on July 25.
There are still no public details about the attacks exploiting the flaw, but CISA has mandated that US Federal Civilian Executive Branch agencies apply patches for it by September 6th, 2023.
Organizations in the private sector should do the same (if they haven’t already). If you’re not sure which storage zones controller you’re using, follow these instructions to find out.
Text extracted automatically; images, tables and formatting may be missing. Original: https://www.helpnetsecurity.com/2023/08/17/cve-2023-24489-exploited/