Cisco AnyConnect Secure Mobility Client for Windows with VPN Posture (HostScan) Module DLL Hijacking Vulnerability
A vulnerability in the interprocess communication (IPC) channel of Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to perform a DLL hijacking attack on an affected device if the VPN Posture (HostScan) Module is installed on the AnyConnect client. This vulnerability is due to insufficient validation of resources that are loaded by the application at run time. An attacker could exploit this vulnerability by sending a crafted IPC message to the AnyConnect process. A successful exploit could allow the attacker to execute arbitrary code on the affected machine with SYSTEM privileges. To exploit this vulnerability, the attacker needs valid credentials on the Windows system.
- Published
- Feb 17, 2021
- Updated
- Jun 16, 2026
- EPSS
- 1.3% · 68th percentile
- CWE
- CWE-347
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.8
- CNA · cisco
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
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 | anyconnect secure mobility client | cpe:2.3:a:cisco:anyconnect_secure_mobility_client |
Using anyconnect secure mobility client? Add it to your stack and be the first to know about CVEs like this one. (VPN gateway)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco anyconnect secure mobility clientbefore 4.9.05042
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.
Cisco Cisco AnyConnect Secure Mobility Client
- n/aaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-3433Cisco AnyConnect Secure Mobility Client for Windows DLL Hijacking VulnerabilityKEV64This week
- CVE-2020-3153Cisco AnyConnect Secure Mobility Client for Windows Uncontrolled Search Path VulnerabilityKEV64This week
- CVE-2011-2039The helper application in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect VPN Client) before 2.3.185 on Windows, and on Windows51Plan
- CVE-2011-2040The helper application in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect VPN Client) before 2.5.3041, and 3.0.x before 3.0.62940Plan
- CVE-2012-3088Cisco AnyConnect Secure Mobility Client 3.1.x before 3.1.00495, and 3.2.x, does not check whether an HTTP request originally contains ScanSa38Monitor
- CVE-2012-2493The VPN downloader implementation in the WebLaunch feature in Cisco AnyConnect Secure Mobility Client 2.x before 2.5 MR6 on Windows, and 2.x38Monitor
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
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:0 | 2023-09-08 |
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.
- Published
- First PoC+932 d
- TodaySep 30, 2026+2051 d
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
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-347 · Improper Verification of Cryptographic SignatureCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Root cause
The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.
The bug in code
The whole CWE-347 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const claims = jwt.verify(token, publicKey);Fixed
const claims = jwt.verify(token, publicKey, { algorithms: ["RS256"], issuer: "https://id.example.com", audience: "portal",});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
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-anyconnect-dll-hijac-JrcTOQMC
Vendor advisories and official records. Exploit/PoC links are deliberately left out.