A vulnerability in the DHCP code for the Zero Touch Provisioning feature of Cisco ASR 920 Series Aggregation Services Routers could allow an
A vulnerability in the DHCP code for the Zero Touch Provisioning feature of Cisco ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a format string vulnerability when processing a crafted DHCP packet for Zero Touch Provisioning. An attacker could exploit this vulnerability by sending a specially crafted DHCP packet to an affected device. An exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco ASR 920 Series Aggregation Services Routers that are running an affected release of Cisco IOS XE Software (3.13 through 3.18) and are listening on the DHCP server port. By default, the devices do not listen on the DHCP server port. Cisco Bug IDs: CSCuy56385.
- Published
- Mar 22, 2017
- Updated
- Jun 16, 2026
- EPSS
- 2.5% · 84th percentile
- CWE
- CWE-134
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.5%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | ios xe | cpe:2.3:o:cisco:ios_xe |
| cisco | asr-920-12cz-a | cpe:2.3:h:cisco:asr-920-12cz-a |
| cisco | asr-920-12cz-d | cpe:2.3:h:cisco:asr-920-12cz-d |
| cisco | asr-920-12sz-im | cpe:2.3:h:cisco:asr-920-12sz-im |
| cisco | asr-920-24sz-im | cpe:2.3:h:cisco:asr-920-24sz-im |
| cisco | asr-920-24sz-m | cpe:2.3:h:cisco:asr-920-24sz-m |
| cisco | asr-920-24tz-m | cpe:2.3:h:cisco:asr-920-24tz-m |
| cisco | asr-920-4sz-a | cpe:2.3:h:cisco:asr-920-4sz-a |
| cisco | asr-920-4sz-d | cpe:2.3:h:cisco:asr-920-4sz-d |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco ios xe3.13.4s
- cisco ios xe3.13.5as
- cisco ios xe3.13.5s
- cisco ios xe3.13.6as
- cisco ios xe3.13.6s
- cisco ios xe3.14.3s
- cisco ios xe3.14.4s
- cisco ios xe3.15.2s
- cisco ios xe3.15.3s
- cisco ios xe3.15.4s
- cisco ios xe3.16.0cs
- cisco ios xe3.16.0s
- cisco ios xe3.16.1as
- cisco ios xe3.16.1s
- cisco ios xe3.16.2as
- cisco ios xe3.16.2bs
- cisco ios xe3.16.2s
- cisco ios xe3.16.3as
- cisco ios xe3.16.3s
- cisco ios xe3.17.0s
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
n/a Cisco IOS XE Software for Cisco ASR 920 Series Routers
- Cisco IOS XE Software for Cisco ASR 920 Series Routersaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-20198Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software.KEV100Now
- CVE-2023-20273A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to inject commands with the priKEV85Now
- CVE-2018-0151A vulnerability in the quality of service (QoS) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, reKEV73This week
- CVE-2025-20188A vulnerability in the Out-of-Band Access Point (AP) Image Download, the Clean Air Spectral Recording, and the client debug bundles features48Plan
- CVE-2019-12643Cisco REST API Container for IOS XE Software Authentication Bypass Vulnerability42Plan
- CVE-2018-0315A vulnerability in the authentication, authorization, and accounting (AAA) security services of Cisco IOS XE Software could allow an unauthe41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-134 · Use of Externally-Controlled Format StringCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.securityfocus.com/bid/97008
- www.securitytracker.com/id/1038104
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170322-ztp
Vendor advisories and official records. Exploit/PoC links are deliberately left out.