SSH 1.2.25, 1.2.23, and other versions, when used in in CBC (Cipher Block Chaining) or CFB (Cipher Feedback 64 bits) modes, allows remote attackers to insert arbitrary data into an existing stream between an SSH client and server by using a known plaintext attack and computing a valid CRC-32 checksum for the packet, aka the "SSH insertion attack."
Conclusion & alert: CVE-1999-1085 is rated Moderate Risk (50.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.16%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-02-17 | 2.95% | 3.16% | +0.21% |
| 2 | 2025-11-28 | 2.08% | 2.95% | +0.88% |
| 3 | 2025-09-29 | — | 2.08% | — |
Full EPSS history (9 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| ssh | secure_shell | 1.2.23 | cpe:2.3:a:ssh:secure_shell:1.2.23:*:*:*:*:*:*:* |
| ssh | secure_shell | 1.2.25 | cpe:2.3:a:ssh:secure_shell:1.2.25:*:*:*:*:*:*:* |