CVE-2020-16139
HighExploitedPublic exploitA denial-of-service in Cisco Unified IP Conference Station 7937G 1-4-4-0 through 1-4-5-7 allows attackers restart the device remotely through sending specially crafted packets.
Published Aug 12, 2020 · Updated Nov 21, 2024
Key Facts
Patch immediately- CVE-2020-16139 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting Unified Ip Conference Station 7937g Firmware (Cisco).
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jun 8, 2025. Public exploit code is available.
- EPSS estimates a 80% probability of exploitation in the next 30 days.
- Fixed versions are available, including Unified Ip Conference Station 7937g Firmware <=1.4.5.7, Unified Ip Conference Station 7937g Firmware 1.4.5.7.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
80%
Higher than 99.6% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2020-16139 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A denial-of-service in Cisco Unified IP Conference Station 7937G 1-4-4-0 through 1-4-5-7 allows attackers restart the device remotely through sending specially crafted packets. Note: We cannot prove this vulnerability exists. Out of an abundance of caution, this CVE is being assigned to better serve our customers and ensure all who are still running this product understand that the product is end of life and should be removed or upgraded. For more information on this, and how to upgrade, refer to the CVE’s reference information
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Jun 8, 2025 | n/a | Not reported |
| CIRCL KEV | Jun 8, 2025 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Unified Ip Conference Station 7937g FirmwareCisco | See advisory | 1.4.5.7 |
Patched Releases
Unified Ip Conference Station 7937g Firmware
<=1.4.5.7
Timeline
Publicly disclosed
Aug 12, 2020
Last updated
Nov 21, 2024
Added to Industry KEV feed
Jun 8, 2025
Added to CIRCL KEV
Jun 8, 2025
References
- advisoryhttps://www.cisco.com/c/en/us/products/collateral/collaboration-endpoints/unified-ip-phone-7940g/end_of_life_notice_c51-729487.html
- exploithttp://packetstormsecurity.com/files/158819/Cisco-7937G-Denial-Of-Service.html
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
A denial-of-service in Cisco Unified IP Conference Station 7937G 1-4-4-0 through 1-4-5-7 allows attackers restart the device remotely through sending specially crafted packets.
Affected: Unified Ip Conference Station 7937g Firmware (Cisco). The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jun 8, 2025.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Unified Ip Conference Station 7937g Firmware <=1.4.5.7, Unified Ip Conference Station 7937g Firmware 1.4.5.7.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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