CISA KEV · catalog date Oct 16, 2023 · first observed Jul 19, 2026
Evidence dossier
CVE-2023-20198
Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software.
Exploited in the wild (CISA KEV since Oct 16, 2023). NVD reports CVSS 3.1 10.0. EPSS estimates 99.6% exploit likelihood as of Aug 7, 2026.
As of Aug 27, 2026
Normalized restatement
Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.
- State
- PUBLISHED
- Published
- Oct 16, 2023
- Updated
- Oct 21, 2025
- Evidence coverage
- 97%
Evidence chronology
What was known when
- Source dateSource date omittedFirst observed by CASCACISA-ADPOriginal evidence ↗
Record text: CISA ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
- Source dateSource date omittedFirst observed by CASCAciscoOriginal evidence ↗
Record text: Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.
Inspect raw assertion
- Field
container- Value
- Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.
- Source dateSource date omittedFirst observed by CASCACVE ProgramOriginal evidence ↗
Record text: CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
- Source dateFirst observed by CASCACISA KEVOriginal evidence ↗
Exploitation cataloged: Cisco IOS XE Web UI Privilege Escalation Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Cisco IOS XE Web UI Privilege Escalation Vulnerability
- Source dateFirst observed by CASCAFIRST EPSSOriginal evidence ↗
EPSS score: 99.57% probability · 99.94th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.995710000000; percentile 0.999440000000
FIRST EPSS · score date Aug 7, 2026 · 99.9th percentile · first observed Aug 7, 2026
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-v1Eligible evidence is present for this bounded claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Aug 27, 2026
- Resolution
- None
Eligible evidence is present for this bounded claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Aug 27, 2026
- Resolution
- None
Eligible evidence is present for this bounded claim.
- Revision
- casca-direct-cvss-eligibility-v1
- Cutoff
- Aug 27, 2026
- Resolution
- None
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 ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.
Inspect raw assertion
- Field
container- Value
- Cisco is providing an update for the ongoing investigation into observed exploitation of the web UI feature in Cisco IOS XE Software. We are updating the list of fixed releases and adding the Software Checker. Our investigation has determined that the actors exploited two previously unknown issues. The attacker first exploited CVE-2023-20198 to gain initial access and issued a privilege 15 command to create a local user and password combination. This allowed the user to log in with normal user access. The attacker then exploited another component of the web UI feature, leveraging the new local user to elevate privilege to root and write the implant to the file system. Cisco has assigned CVE-2023-20273 to this issue. CVE-2023-20198 has been assigned a CVSS Score of 10.0. CVE-2023-20273 has been assigned a CVSS Score of 7.2. Both of these CVEs are being tracked by CSCwh87343.
CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
Cisco IOS XE Web UI Privilege Escalation Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Cisco IOS XE Web UI Privilege Escalation Vulnerability
99.57% probability · 99.94th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.995710000000; percentile 0.999440000000
Applicability
Cited product scope
Grouped from 5 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 2026-07-21T06:45:29.809Z
27d65b0f-b718-4b4f-bb79-c47c68d09dfa - Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z
955dae73-7302-438b-aee1-058d7cc5d48e
6 scope groups
Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "16.1.1"}, {"status": "affected", "version": "16.1.2"}, {"status": "affected", "version": "16.1.3"}, {"status": "affected", "version": "16.2.1"}, {"status": "affected", "version": "16.2.2"}, {"status": "affected", "version": "16.3.1"}, {"status": "affected", "version": "16.3.2"}, {"status": "affected", "version": "16.3.3"}, {"status": "affected", "version": "16.3.1a"}, {"status": "affected", "version": "16.3.4"}, {"status": "affected", "version": "16.3.5"}, {"status": "affected", "version": "16.3.5b"}, {"status": "affected", "version": "16.3.6"}, {"status": "affected", "version": "16.3.7"}, {"status": "affected", "version": "16.3.8"}, {"status": "affected", "version": "16.3.9"}, {"status": "affected", "version": "16.3.10"}, {"status": "affected", "version": "16.3.11"}, {"status": "affected", "version": "16.4.1"}, {"status": "affected", "version": "16.4.2"}, {"status": "affected", "version": "16.4.3"}, {"status": "affected", "version": "16.5.1"}, {"status": "affected", "version": "16.5.1a"}, {"status": "affected", "version": "16.5.1b"}, {"status": "affected", "version": "16.5.2"}, {"status": "affected", "version": "16.5.3"}, {"status": "affected", "version": "16.6.1"}, {"status": "affected", "version": "16.6.2"}, {"status": "affected", "version": "16.6.3"}, {"status": "affected", "version": "16.6.4"}, {"status": "affected", "version": "16.6.5"}, {"status": "affected", "version": "16.6.4a"}, {"status": "affected", "version": "16.6.5a"}, {"status": "affected", "version": "16.6.6"}, {"status": "affected", "version": "16.6.7"}, {"status": "affected", "version": "16.6.8"}, {"status": "affected", "version": "16.6.9"}, {"status": "affected", "version": "16.6.10"}, {"status": "affected", "version": "16.7.1"}, {"status": "affected", "version": "16.7.1a"}, {"status": "affected", "version": "16.7.1b"}, {"status": "affected", "version": "16.7.2"}, {"status": "affected", "version": "16.7.3"}, {"status": "affected", "version": "16.7.4"}, {"status": "affected", "version": "16.8.1"}, {"status": "affected", "version": "16.8.1a"}, {"status": "affected", "version": "16.8.1b"}, {"status": "affected", "version": "16.8.1s"}, {"status": "affected", "version": "16.8.1c"}, {"status": "affected", "version": "16.8.1d"}, {"status": "affected", "version": "16.8.2"}, {"status": "affected", "version": "16.8.1e"}, {"status": "affected", "version": "16.8.3"}, {"status": "affected", "version": "16.9.1"}, {"status": "affected", "version": "16.9.2"}, {"status": "affected", "version": "16.9.1a"}, {"status": "affected", "version": "16.9.1b"}, {"status": "affected", "version": "16.9.1s"}, {"status": "affected", "version": "16.9.3"}, {"status": "affected", "version": "16.9.4"}, {"status": "affected", "version": "16.9.3a"}, {"status": "affected", "version": "16.9.5"}, {"status": "affected", "version": "16.9.5f"}, {"status": "affected", "version": "16.9.6"}, {"status": "affected", "version": "16.9.7"}, {"status": "affected", "version": "16.9.8"}, {"status": "affected", "version": "16.10.1"}, {"status": "affected", "version": "16.10.1a"}, {"status": "affected", "version": "16.10.1b"}, {"status": "affected", "version": "16.10.1s"}, {"status": "affected", "version": "16.10.1c"}, {"status": "affected", "version": "16.10.1e"}, {"status": "affected", "version": "16.10.1d"}, {"status": "affected", "version": "16.10.2"}, {"status": "affected", "version": "16.10.1f"}, {"status": "affected", "version": "16.10.1g"}, {"status": "affected", "version": "16.10.3"}, {"status": "affected", "version": "16.11.1"}, {"status": "affected", "version": "16.11.1a"}, {"status": "affected", "version": "16.11.1b"}, {"status": "affected", "version": "16.11.2"}, {"status": "affected", "version": "16.11.1s"}, {"status": "affected", "version": "16.12.1"}, {"status": "affected", "version": "16.12.1s"}, {"status": "affected", "version": "16.12.1a"}, {"status": "affected", "version": "16.12.1c"}, {"status": "affected", "version": "16.12.1w"}, {"status": "affected", "version": "16.12.2"}, {"status": "affected", "version": "16.12.1y"}, {"status": "affected", "version": "16.12.2a"}, {"status": "affected", "version": "16.12.3"}, {"status": "affected", "version": "16.12.8"}, {"status": "affected", "version": "16.12.2s"}, {"status": "affected", "version": "16.12.1x"}, {"status": "affected", "version": "16.12.1t"}, {"status": "affected", "version": "16.12.4"}, {"status": "affected", "version": "16.12.3s"}, {"status": "affected", "version": "16.12.3a"}, {"status": "affected", "version": "16.12.4a"}, {"status": "affected", "version": "16.12.5"}, {"status": "affected", "version": "16.12.6"}, {"status": "affected", "version": "16.12.1z1"}, {"status": "affected", "version": "16.12.5a"}, {"status": "affected", "version": "16.12.5b"}, {"status": "affected", "version": "16.12.1z2"}, {"status": "affected", "version": "16.12.6a"}, {"status": "affected", "version": "16.12.7"}, {"status": "affected", "version": "16.12.9"}, {"status": "affected", "version": "16.12.10"}, {"status": "affected", "version": "17.1.1"}, {"status": "affected", "version": "17.1.1a"}, {"status": "affected", "version": "17.1.1s"}, {"status": "affected", "version": "17.1.1t"}, {"status": "affected", "version": "17.1.3"}, {"status": "affected", "version": "17.2.1"}, {"status": "affected", "version": "17.2.1r"}, {"status": "affected", "version": "17.2.1a"}, {"status": "affected", "version": "17.2.1v"}, {"status": "affected", "version": "17.2.2"}, {"status": "affected", "version": "17.2.3"}, {"status": "affected", "version": "17.3.1"}, {"status": "affected", "version": "17.3.2"}, {"status": "affected", "version": "17.3.3"}, {"status": "affected", "version": "17.3.1a"}, {"status": "affected", "version": "17.3.1w"}, {"status": "affected", "version": "17.3.2a"}, {"status": "affected", "version": "17.3.1x"}, {"status": "affected", "version": "17.3.1z"}, {"status": "affected", "version": "17.3.4"}, {"status": "affected", "version": "17.3.5"}, {"status": "affected", "version": "17.3.4a"}, {"status": "affected", "version": "17.3.6"}, {"status": "affected", "version": "17.3.4b"}, {"status": "affected", "version": "17.3.4c"}, {"status": "affected", "version": "17.3.5a"}, {"status": "affected", "version": "17.3.5b"}, {"status": "affected", "version": "17.3.7"}, {"status": "affected", "version": "17.3.8"}, {"status": "affected", "version": "17.4.1"}, {"status": "affected", "version": "17.4.2"}, {"status": "affected", "version": "17.4.1a"}, {"status": "affected", "version": "17.4.1b"}, {"status": "affected", "version": "17.4.2a"}, {"status": "affected", "version": "17.5.1"}, {"status": "affected", "version": "17.5.1a"}, {"status": "affected", "version": "17.5.1b"}, {"status": "affected", "version": "17.5.1c"}, {"status": "affected", "version": "17.6.1"}, {"status": "affected", "version": "17.6.2"}, {"status": "affected", "version": "17.6.1w"}, {"status": "affected", "version": "17.6.1a"}, {"status": "affected", "version": "17.6.1x"}, {"status": "affected", "version": "17.6.3"}, {"status": "affected", "version": "17.6.1y"}, {"status": "affected", "version": "17.6.1z"}, {"status": "affected", "version": "17.6.3a"}, {"status": "affected", "version": "17.6.4"}, {"status": "affected", "version": "17.6.1z1"}, {"status": "affected", "version": "17.6.5"}, {"status": "affected", "version": "17.6.6"}, {"status": "affected", "version": "17.7.1"}, {"status": "affected", "version": "17.7.1a"}, {"status": "affected", "version": "17.7.1b"}, {"status": "affected", "version": "17.7.2"}, {"status": "affected", "version": "17.10.1"}, {"status": "affected", "version": "17.10.1a"}, {"status": "affected", "version": "17.10.1b"}, {"status": "affected", "version": "17.8.1"}, {"status": "affected", "version": "17.8.1a"}, {"status": "affected", "version": "17.9.1"}, {"status": "affected", "version": "17.9.1w"}, {"status": "affected", "version": "17.9.2"}, {"status": "affected", "version": "17.9.1a"}, {"status": "affected", "version": "17.9.1x"}, {"status": "affected", "version": "17.9.1y"}, {"status": "affected", "version": "17.9.3"}, {"status": "affected", "version": "17.9.2a"}, {"status": "affected", "version": "17.9.1x1"}, {"status": "affected", "version": "17.9.3a"}, {"status": "affected", "version": "17.9.4"}, {"status": "affected", "version": "17.9.1y1"}, {"status": "affected", "version": "17.11.1"}, {"status": "affected", "version": "17.11.1a"}, {"status": "affected", "version": "17.12.1"}, {"status": "affected", "version": "17.12.1a"}, {"status": "affected", "version": "17.11.99SW"}]product-cc06181059d0f387414dd5737700c03a38fe93d65d4a541ac9744a37c25c9f59Linked exactInspect raw assertions
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 2 · node/0 · match 2
- Logic
- OR
- Version bounds
- from including 17.6; through excluding 17.6.6a
- Match ID
281561c8-e24d-4ac1-b1f8-1d32171b9a2f
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 2 · node/0 · match 3
- Logic
- OR
- Version bounds
- from including 17.9; through excluding 17.9.4a
- Match ID
b628da7f-32aa-459b-95a6-af3bfc0e765c
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 2 · node/0 · match 0
- Logic
- OR
- Version bounds
- from including 16.12; through excluding 16.12.10a
- Match ID
2c8a350d-6c3a-430f-9763-5d167c5ceae5
cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 2 · node/0 · match 1
- Logic
- OR
- Version bounds
- from including 17.3; through excluding 17.3.8a
- Match ID
bea2169a-be52-48b4-8967-d99a4bcaff58
product-24bdcd14c7abbe1544412cf5296e70941d468a9099de512856425822457c81cfLinked exactInspect raw assertion
cpe:2.3:h:rockwellautomation:allen-bradley_stratix_5200:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Environmental constraint
- Configuration
- 0 · node/1 · match 0
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
11aa4eeb-01cc-4d7d-bed0-26d208667fb4
product-edc1ab1531776d3ba292d5a5c9ee4e02bb6086c6b1230b85c2f3175ecffeaf58Linked exactInspect raw assertion
cpe:2.3:o:rockwellautomation:allen-bradley_stratix_5200_firmware:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 17.12.02
- Match ID
a45c356a-6a37-4db6-8d25-546b364076d5
product-ecfb33ed538a7773850412063cb90a6926c9519c45ba5cde4b6a3709d50a0b2fLinked exactInspect raw assertion
cpe:2.3:h:rockwellautomation:allen-bradley_stratix_5800:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Environmental constraint
- Configuration
- 1 · node/1 · match 0
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
832effe6-1c38-47b9-95f1-f3fbc785fa27
product-eebd7eec19bcc600677b4a8056f22e249eb16b9a5af596b10a9e3fe68caba083Linked exactInspect raw assertion
cpe:2.3:o:rockwellautomation:allen-bradley_stratix_5800_firmware:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 1 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 17.12.02
- Match ID
57e85d08-12aa-4ec4-946a-3f0614f2e45e
Affected-product evidence
Accepted scope and product mapping
3 canonical links · 1 source-reported links
vendor-0774b265c0e837e737aaf99ed0f2450c048e61f34267ca59d8623878b839334e · product-cc06181059d0f387414dd5737700c03a38fe93d65d4a541ac9744a37c25c9f59
- Source class
- Nvd cpe vulnerable target
- Assertions
- 4
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
404f4afa-3baa-4478-92ea-bda4f898f20b7560622d-3284-4ebf-b505-94170c60220581d008e5-5b86-44c7-803d-a34067b10deeb2e0239b-1207-4e22-97d6-8502d9701ca6vendor-c4d6775ce29222cdb0b7d7810ba87d2e4be2e981e2c873e80c97672aafc978dc · product-edc1ab1531776d3ba292d5a5c9ee4e02bb6086c6b1230b85c2f3175ecffeaf58
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
b28126b9-68b5-42bd-b583-f9734bc0a45fvendor-c4d6775ce29222cdb0b7d7810ba87d2e4be2e981e2c873e80c97672aafc978dc · product-eebd7eec19bcc600677b4a8056f22e249eb16b9a5af596b10a9e3fe68caba083
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
fab14cbe-45a6-40ae-9cea-cb4d22994ef4Canonical 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
ab4c89b9-9d41-4e91-9212-70153277d07fAssessments
CVSS by origin
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HDirect CVE/CNA normalized decisions
cisco
CVSS 3.1 · Primary · Original assertion · rank 1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- Validation
- Valid match
- Recomputed
- 10.0
- 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.