CVE-2017-6627
HighExploitedPublic exploitA vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service…
Published Sep 7, 2017 · Updated Apr 22, 2026
Key Facts
Patch immediately- CVE-2017-6627 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting IOS (Cisco), IOS Xe (Cisco), Cisco IOS and Cisco IOS XE.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2022. Public exploit code is available.
- EPSS estimates a 6.2% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- 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)
6.2%
Higher than 93.3% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2017-6627 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition. The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets. Cisco Bug IDs: CSCup10024, CSCva55744, CSCva95506.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 3, 2022 | Mar 24, 2022 | Not reported |
| Industry KEV feed | Mar 3, 2022 | Mar 24, 2022 | Not reported |
| CIRCL KEV | Mar 3, 2022 | Mar 24, 2022 | Not reported |
| ENISA EUVD | Mar 3, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
72 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOSCisco | 15.1\(2\)gc, 15.1\(2\)gc1, 15.1\(2\)gc2, 15.1\(4\)gc, 15.1\(4\)gc1, 15.1\(4\)gc2, 15.2\(1\)gc, 15.2\(1\)gc1 | n/a |
| IOS XeCisco | 3.14.0s, 3.14.1s, 3.14.2s, 3.14.3s, 3.14.4s, 3.15.0s, 3.15.1cs, 3.15.1s | n/a |
| Cisco IOS and Cisco IOS XE | >= Cisco IOS and Cisco IOS XE | n/a |
Timeline
Publicly disclosed
Sep 7, 2017
Added to CISA KEV
Mar 3, 2022
Added to Industry KEV feed
Mar 3, 2022
Added to CIRCL KEV
Mar 3, 2022
Added to ENISA EUVD
Mar 3, 2022
Last updated
Apr 22, 2026
Weakness Type
- CWE-399
- CWE-404 Improper Resource Shutdown or Release
References
- advisoryhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ios-udp
- advisory100644
- advisory1039289
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition.
Affected: IOS (Cisco) versions 15.1\(2\)gc, 15.1\(2\)gc1, 15.1\(2\)gc2, 15.1\(4\)gc, 15.1\(4\)gc1, 15.1\(4\)gc2, 15.2\(1\)gc, 15.2\(1\)gc1; IOS Xe (Cisco) versions 3.14.0s, 3.14.1s, 3.14.2s, 3.14.3s, 3.14.4s, 3.15.0s, 3.15.1cs, 3.15.1s; Cisco IOS and Cisco IOS XE versions >= Cisco IOS and Cisco IOS XE. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2022.
Yes. It was added on Mar 3, 2022 with a federal remediation due date of Mar 24, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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