CVE-2023-24489
CVE-2023-24489 is a security flaw in Citrix Content Collaboration, the gateway companies use to let staff reach internal apps from outside. Attackers can reach parts of Citrix Content Collaboration that should be locked to them from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 16 Aug 2023.[1]
Citrix Content Collaboration is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 5.11.24 of Citrix ShareFile Storage Zones Controller.
Description
CISA calls it a shareFile improper access control in Citrix Content Collaboration. In its words: “Citrix Content Collaboration contains an improper access control vulnerability that could allow an unauthenticated attacker to remotely compromise customer-managed ShareFile storage zones controllers.”[1]
The underlying weakness is improper access control (CWE-284), in MITRE’s list of common software weaknesses.[2]
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists one fixed version: everything before it is affected.[2]
| Product | Fixed in |
|---|---|
| Citrix ShareFile Storage Zones Controller | 5.11.24 |
Most families won’t have Citrix Content Collaboration; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 16 Aug 2023, 37 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 6 Sep 2023 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 97%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Citrix has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Citrix Content Collaboration is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 5.11.24 of Citrix ShareFile Storage Zones Controller), or not in use. CISA gave US government agencies until 6 Sep 2023 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 97%.[4] |
See also
Other Citrix flaws
- CVE-2026-88779, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88772, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88771, Citrix NetScaler: improper input validation ·
- CVE-2026-19490, Citrix NetScaler: authentication bypass using an alternate path or channel ·
- CVE-2026-8452, Citrix NetScaler ADC and NetScaler Gateway: improper restriction of operations within the bounds of a memory buffer ·
Other improper access control flaws
- CVE-2015-3306, ProFTPD: improper access control ·
- CVE-2026-21962, Oracle HTTP Server and Oracle Weblogic Server Proxy Plug-in: improper access control ·
- CVE-2026-56290, Joomlack Page Builder: improper access control ·
- CVE-2026-34908, Ubiquiti UniFi OS: improper access control ·
- CVE-2026-48907, Widget Factory Joomla Content Editor: improper access control ·
Every Citrix flaw on CISA’s list · Everything added in August 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Citrix Content Collaboration ShareFile Improper Access Control Vulnerability”. Known Exploited Vulnerabilities Catalog, added 16 Aug 2023.
- ^ National Institute of Standards and Technology. “CVE-2023-24489 Detail”. National Vulnerability Database, published 10 Jul 2023.
- ^ Citrix. Advisories and fixes: support.citrix.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.973, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2023-24489”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.