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Full vulnerability report · 2016
CVE-2016-9212High confidence

n/a Cisco Web Security Appliance: Improper Input Validation

Unknown · Cisco Web Security Appliance

Official source article: Cisco CISCO-SA-20161207-WSA1 ↗. Check the applicable product and release in the original source.

7.5HighCVSS 3.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 2.79% for the current model date.

Compensating controls

  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown Cisco Web Security Appliance and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2016-10024

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

A vulnerability in the Decrypt for End-User Notification configuration parameter of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, remote attacker to connect to a secure website over Secure Sockets Layer (SSL) or Transport Layer Security (TLS), even if the WSA is configured to block connections to the website. Affected Products: This vulnerability affects Cisco Web Security Appliances if the HTTPS decryption options are enabled and configured for the device to block connections to certain websites. More Information: CSCvb49012. Known Affected Releases: 9.0.1-162 9.1.1-074.

What

A vulnerability in the Decrypt for End-User Notification configuration parameter of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, remote attacker to connect to a secure website over Secure Sockets Layer (SSL) or Transport Layer Security (TLS), even if the WSA is configured to block connections to the website. Affected Products: This vulnerability affects Cisco Web Security Appliances if the HTTPS decryption options are enabled and configured for the device to block connections to certain websites. More Information: CSCvb49012. Known Affected Releases: 9.0.1-162 9.1.1-074.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A vulnerability in the Decrypt for End-User Notification configuration parameter of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, remote attacker to connect to a secure website over Secure Sockets Layer (SSL) or Transport Layer Security (TLS), even if the WSA is configured to block connections to the website. Affected Products: This vulnerability affects Cisco Web Security Appliances if the HTTPS decryption options are enabled and configured for the device to block connections to certain websites. More Information: CSCvb49012. Known Affected Releases: 9.0.1-162 9.1.1-074.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Common Vulnerability Scoring System 3.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-20
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Canadian Centre for Cyber Security · English · AV17-149Cisco security updates

isco Web Security Appliance Cisco Adaptive Security Appliance Cisco WebEx Meetings Cisco Wide Area Application Services ICA Cisco Wide Area Application Services Cisco Unified Communications Manager Cisco Spark Messaging Stored Cisco IOS XR Software Cisco Meeting Server Cisco Meeting App Cisco AnyConnect Network Access Manager Cisco Integrated Management Controller Cisco Integrated Management Controller Cisco IOS Software for Cisco Industrial Ethernet Switches PROFINET CVE References:  CVE-2017-12268, CVE-2017-12266, CVE-2017-12264, CVE-2017-12270, CVE-2017-12269, CVE-2017-12258, CVE-2017-12256, CVE-2017-12267, CVE-2017-12257, CVE-2017-12265, CVE-2016-9212, CVE-2017-12246, CVE-2017-12263,  CVE-2017-12244, CVE-2017-12245, CVE-2017-6616, CVE-2017-9793, CVE-2017-9804, CVE-2017-12611, CVE-2017-6619, CVE-2017-12235 Suggested Action CCIRC recommends that system administrators test and deploy the vendor-released updates to affected applications accordingly. References: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171004-ftd https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171004-fpsnort https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171004-clm https://tools.cisco.com/security/center/content/CiscoSecu

Official advisory ↗
Canadian Centre for Cyber Security · English · AV16-208Cisco Releases security updates

179, CVE-2016-2180, CVE-2016-2181, CVE-2016-2182, CVE-2016-2183, CVE-2016-6302, CVE-2016-6303, CVE-2016-6304, CVE-2016-6305, CVE-2016-6306, CVE-2016-6307, CVE-2016-6308, CVE-2016-6309, CVE-2016-7052, CVE-2016-7053, CVE-2016-7054, CVE-2016-7055, CVE-2016-9192, CVE-2016-6467, CVE-2016-9203, CVE-2016-1411, CVE-2016-9199, CVE-2016-6468, CVE-2016-9208, CVE-2016-9211, CVE-2016-9206, CVE-2016-9210, CVE-2016-9202, CVE-2016-6449, CVE-2016-9193, CVE-2016-9209, CVE-2016-6470, CVE-2016-9204, CVE-2016-6473, CVE-2016-6474, CVE-2016-9205, CVE-2016-9201, CVE-2016-9215, CVE-2016-9198, CVE-2016-9214, CVE-2016-9200, CVE-2016-6464, CVE-2016-6471, CVE-2016-6469, CVE-2016-9212, CVE-2016-5195, CVE-2016-6465, CVE-2015-8138, CVE-2016-7426, CVE-2016-7427, CVE-2016-9207, CVE-2016-9217, CVE-2016-9224 Suggested action CCIRC recommends that system administrators test and deploy the vendor-released updates to affected applications accordingly. References https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161115-iosxe https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161116-asa https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161116-esa1 https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161116-esa2 htt

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2016-006308Cisco Web セキュリティ アプライアンス用 AsyncOS の End-User Notification 設定パラメータにおけるブロック設定を回避される脆弱性

Cisco Web セキュリティ アプライアンス (WSA) 用 AsyncOS の End-User Notification 設定パラメータには、接続をブロックするように設定されているにも関わらず、SSL (Secure Sockets Layer) または TLS (Transport Layer Security) 上の Web サイトへ接続される脆弱性が存在します。 ベンダは、本脆弱性を Bug ID CSCvb49012 として公開しています。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-4783Cisco 제품군 취약점 보안 업데이트 권고

Cisco Web Security Appliance의 암호 해독 정책 우회 취약점(CVE-2016-9212) [21]

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
Cisco Web Security Appliance: Cisco Web Security Appliance
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 14 Dec 2016 · Last source change 6 Aug 2024, 02:42 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-01
European sourceENISA EUVD · EUVD-2016-10024
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2016-10024 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2016-10024"}
    ENISA EUVD ↗
  2. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: tools.cisco.com/cisco-sa-20161207-wsa1.
    Before
    no authoritative guidance recorded
    After
    vendor advisory: tools.cisco.com/cisco-sa-20161207-wsa1
    tools.cisco.com ↗
  3. SeveritySeverity changed from Unknown to High.
    Before
    Unknown
    After
    High
    NIST NVD ↗
  4. CVSS scoreCVSS score changed from not recorded to 7.5 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).
    Before
    not recorded
    After
    7.5 (CVSS 3.0 · NIST NVD · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
    NIST NVD ↗
  5. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2016-10024↗CVE authority or vendor reference · Cisco CISCO-SA-20161207-WSA1↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2016-9212 · cve.blacktree.nl