CASCACascade Atlas

Evidence dossier

CVE-2018-0172

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an…

Exploited in the wild (CISA KEV since Mar 3, 2022). NVD reports CVSS 3.1 8.6. EPSS estimates 7.9% exploit likelihood as of Aug 27, 2026.

70.6–71.9Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

State
PUBLISHED
Published
Mar 28, 2018
Updated
Jan 12, 2026
Evidence coverage
97%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    cisco

    Record text: A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

    Inspect raw assertion
    Field
    container
    Value
    A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 7.87% probability · 94.26th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.078710000000; percentile 0.942590000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Mar 3, 2022 · first observed Jul 19, 2026

Exploit likelihood7.87%

FIRST EPSS · score date Aug 27, 2026 · 94.3th percentile · first observed Aug 27, 2026

SeverityCVSS 8.6

NVD · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
ciscoOriginal assertion
Record text

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

Inspect raw assertion
Field
container
Value
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Cisco IOS and IOS XE Software Improper Input Validation Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

7.87% probability · 94.26th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.078710000000; percentile 0.942590000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
10Underlying assertions
8Canonical products
4Target assertions
6Constraint assertions

Grouped from 3 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

9 scope groups

cisco · source assertedn/aCisco IOS and IOS XEDirect source scope
Affected: Cisco IOS and IOS XE
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "Cisco IOS and IOS XE"}]
NVD CPE · OPERATING SYSTEMciscoiosVulnerable target · 2 assertions
Version not applicableCanonical identity product-5972f4392170d0d1b4e75a10eb3b383835ead601c8d9b09329525407a4e1471aLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:cisco:ios:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b6230a85-30d2-4934-a8a0-11499b7b09f8
  2. cpe:2.3:o:cisco:ios:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b6230a85-30d2-4934-a8a0-11499b7b09f8
NVD CPE · OPERATING SYSTEMciscoios_xeVulnerable target · 2 assertions
Version not applicableCanonical identity product-cc06181059d0f387414dd5737700c03a38fe93d65d4a541ac9744a37c25c9f59Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:cisco:ios_xe:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    1 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b7d95e8a-8f0b-44e5-b266-09e10baaec55
  2. cpe:2.3:o:cisco:ios_xe:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b7d95e8a-8f0b-44e5-b266-09e10baaec55
NVD CPE · HARDWARErockwellautomationallen-bradley_armorstratix_5700Environmental constraint · 1 assertions
Version not applicableCanonical identity product-0ba0da2d834f87957eb2cbbe8af7841f85bd29dcc7b144dd62a938a904738cabLinked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_armorstratix_5700:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    d8849345-e011-4160-a91c-db760497af9a
NVD CPE · HARDWARErockwellautomationallen-bradley_stratix_5400Environmental constraint · 1 assertions
Version not applicableCanonical identity product-711b032049212e8ff976133d7f8f20aec23230664475ea9b655ebccc5d41c46dLinked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_stratix_5400:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    de92939d-3d1e-445c-8888-f3eb4e35a034
NVD CPE · HARDWARErockwellautomationallen-bradley_stratix_5410Environmental constraint · 1 assertions
Version not applicableCanonical identity product-e72ed84163580f65db57520117a86ed0e31a384d4f4e31881f6f6a03a4f1db25Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_stratix_5410:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    0b148d62-d1b2-4e40-9ddd-a8702dfad2e4
NVD CPE · HARDWARErockwellautomationallen-bradley_stratix_5700Environmental constraint · 1 assertions
Version not applicableCanonical identity product-76672eb41960e7205c5e12de199412ca0600e80bd3c265e838644bb7593a9396Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_stratix_5700:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    8994dea7-c4ec-47b9-8aea-832af9d1f8e4
NVD CPE · HARDWARErockwellautomationallen-bradley_stratix_8000Environmental constraint · 1 assertions
Version not applicableCanonical identity product-fbdfd1fd0d57143f69346d569adf8ea0acd2152416922dfa1455ed199d755fceLinked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_stratix_8000:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    f9a02987-e6f4-41d2-92c5-016a22ac7d0a
NVD CPE · HARDWARErockwellautomationallen-bradley_stratix_8300Environmental constraint · 1 assertions
Version not applicableCanonical identity product-93072d5959f2cbb5479254c634f0df57f9e5d74e379076ba09fc46742636fcb7Linked exact
Scope constrained
Inspect raw assertion
  1. cpe:2.3:h:rockwellautomation:allen-bradley_stratix_8300:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Environmental constraint
    Configuration
    1 · node/1 · match 5
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    3a97b3b5-6606-46f5-bcd8-141fdd6f6729

Affected-product evidence

Accepted scope and product mapping

2 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-0774b265c0e837e737aaf99ed0f2450c048e61f34267ca59d8623878b839334e · product-5972f4392170d0d1b4e75a10eb3b383835ead601c8d9b09329525407a4e1471a

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
40229efd-6848-4bae-96dc-52e61de2ef4bae1512a0-ce22-4770-882a-38a79382eb79
Mapping establishedEvidence supported

vendor-0774b265c0e837e737aaf99ed0f2450c048e61f34267ca59d8623878b839334e · product-cc06181059d0f387414dd5737700c03a38fe93d65d4a541ac9744a37c25c9f59

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
a0d6a6bd-e726-4f25-8894-5d9a840ff7a7c96ebc23-a015-49de-8415-133e0a9fbcbb
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
0bd421eb-979f-4293-be06-cda275ab07f9

Assessments

CVSS by origin

8.6
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
7.8
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:N/I:N/A:C
8.6
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
8.6
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Direct CVE/CNA normalized decisions

8.6Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Validation
Valid match
Recomputed
8.6
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.