CVE-2019-5544
OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. VMware has evaluated the severity of this issue to be…
- 9.8CriticalCVSS base score
- 98.1%Exploitation in 30 daysEPSS · top 0.1% of all CVEs
- YesKnown exploitedin CISA's KEV since 3 Nov 2021
- 1Public exploitsMetasploit, Nuclei and Exploit-DB
Description
OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Vulnerability.
- Added
- 3 Nov 2021
- Fix due (US federal)
- 3 May 2022
- Used by ransomware
- Known
Apply updates per vendor instructions.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV, since 3 Nov 2021.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Nuclei template for it. CISA's SSVC rates its exploitation: it is being exploited.
Show the exploits1
Nuclei templates1 template
- VMware ESXi SLP - Heap Overflow DoS (Nuclei template) (opens in a new tab)
network/cves/2019/CVE-2019-5544.yamlSeverity critical
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By vmware
- 11 months later
· 11 months later
Published
- 23 months later
· 23 months later
Added to CISA KEV
Known exploited, also by ransomware
- 4 years later
· 4 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 98.1% · top 0.1% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
ESXi and Horizon DaaS
- affected ESXi 6.7 prior to patch release ESXi670-201912001, ESXi 6.5 prior to patch release ESXi650-201912001, ESXi 6.0 prior to patch release ESXi600-201912001 and Horizon DaaS 8.x prior to BZ-2467224-Disable_SLPD_service_permanently_801_Hotfix.
References
9
- http://www.vmware.com/security/advisories/VMSA-2019-0022.html (opens in a new tab)x_refsource_CONFIRMx_transferred
- [oss-security] 20191210 Re: CVE-2019-5544 openslp 1.2.1, 2.0.0 heap overflow vulnerability (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- [oss-security] 20191211 Re: CVE-2019-5544 openslp 1.2.1, 2.0.0 heap overflow vulnerability (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
- RHSA-2019:4240 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- FEDORA-2019-1e5ae33e87 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- FEDORA-2019-86bceb61b3 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
- RHSA-2020:0199 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- GLSA-202005-12 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2019-5544 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2019-15119 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2019-5544)Record last updated .