medium Known exploitedREV. 01
CVE-2023-20109Cisco routers — encrypted transport writes out of bounds
The group encrypted transport feature (GET VPN) in Cisco's router software does not validate the attributes it is handed, so an attacker controlling a key server or a group member runs code on the device or reloads it.
Read the risk
THE VITAL STATS- CVSS score
- 6.6/ 10 CVSS v3.1
- EPSS probability
- 2% Likelihood of exploitation
- Attack complexity
- High Conditions needed to exploit
- Known exploited
- Yes — CISA KEV
- CVE published
- 2023-09-27
- Added to KEV
- 2023-10-10
- Exploit published
- Not recorded
- Confidence
- high
- Kill chain
- execution
- MITRE ATT&CK
- T1190
- Severity
- medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Attacker needsAdministrative control of either a key server or a group member in the encrypted group.
Behind the card
3 REFERENCES- 01CVE recordNVD recordnvd.nist.gov
- 02CISACISA Known Exploited Vulnerabilities catalogcisa.gov
- 03Vendor advisorysec.cloudapps.cisco.comsec.cloudapps.cisco.com
Field-level provenanceTRACE THE SOURCES +
Which source supports each field, when it was retrieved, and who extracted it.
| Fields | Source | Retrieved | Extractor | Confidence |
|---|---|---|---|---|
| cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_at | nvd.nist.gov | 2026-09-24 | scrty-crds-pipeline/0.1 | high |
| exploitation.known_exploited, exploitation.kev_added | cisa.gov | 2026-09-24 | scrty-crds-pipeline/0.1 | high |
| epss | api.first.org | 2026-09-24 | scrty-crds-pipeline/0.1 | high |
| title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisites | nvd.nist.gov | 2026-09-24 | claude-code | high |
Printing history
THE RECORD- r1Initial base card
First printing. This card has not been reprinted since publication.