CVE-2020-3200 | Cisco IOS and IOS XE Software Secure Shell Denial of Service Vulnerability

A vulnerability in the Secure Shell (SSH) server code of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to cause an affected device to reload. The vulnerability is due to an internal state not being represented correctly in the SSH state machine, which leads to an unexpected behavior. An attacker could exploit this vulnerability by creating an SSH connection to an affected device and using a specific traffic pattern that causes an error condition within that connection. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

Published: 2020-06-03 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-3200 is rated Moderate Risk (58.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.72%). EPSS rose +1.41% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-3200

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 2026-06-15 0.31% 1.72% +1.41%
2 2025-11-21 0.43% 0.31% -0.12%
3 2025-11-18 — 0.43% —

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3200

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.7 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 4.0 [email protected]
7.7 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 4.0 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:L/Au:S/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.0 6.9 [email protected]

Weakness enumeration for CVE-2020-3200

Affected software / configurations for CVE-2020-3200

Vendor Product Version Raw CPE
cisco ios 12.2\(6\)i1 cpe:2.3:o:cisco:ios:12.2\(6\)i1:*:*:*:*:*:*:*
cisco ios 12.2\(58\)ex cpe:2.3:o:cisco:ios:12.2\(58\)ex:*:*:*:*:*:*:*
cisco ios 12.2\(58\)ey cpe:2.3:o:cisco:ios:12.2\(58\)ey:*:*:*:*:*:*:*
cisco ios 12.2\(58\)ey1 cpe:2.3:o:cisco:ios:12.2\(58\)ey1:*:*:*:*:*:*:*
cisco ios 12.2\(58\)ey2 cpe:2.3:o:cisco:ios:12.2\(58\)ey2:*:*:*:*:*:*:*
cisco ios 12.2\(58\)ez cpe:2.3:o:cisco:ios:12.2\(58\)ez:*:*:*:*:*:*:*
cisco ios 12.2\(58\)se cpe:2.3:o:cisco:ios:12.2\(58\)se:*:*:*:*:*:*:*
cisco ios 12.2\(58\)se1 cpe:2.3:o:cisco:ios:12.2\(58\)se1:*:*:*:*:*:*:*
cisco ios 12.2\(58\)se2 cpe:2.3:o:cisco:ios:12.2\(58\)se2:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez cpe:2.3:o:cisco:ios:12.2\(60\)ez:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez1 cpe:2.3:o:cisco:ios:12.2\(60\)ez1:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez2 cpe:2.3:o:cisco:ios:12.2\(60\)ez2:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez3 cpe:2.3:o:cisco:ios:12.2\(60\)ez3:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez4 cpe:2.3:o:cisco:ios:12.2\(60\)ez4:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez5 cpe:2.3:o:cisco:ios:12.2\(60\)ez5:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez6 cpe:2.3:o:cisco:ios:12.2\(60\)ez6:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez7 cpe:2.3:o:cisco:ios:12.2\(60\)ez7:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez8 cpe:2.3:o:cisco:ios:12.2\(60\)ez8:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez9 cpe:2.3:o:cisco:ios:12.2\(60\)ez9:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez10 cpe:2.3:o:cisco:ios:12.2\(60\)ez10:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez11 cpe:2.3:o:cisco:ios:12.2\(60\)ez11:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez12 cpe:2.3:o:cisco:ios:12.2\(60\)ez12:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez13 cpe:2.3:o:cisco:ios:12.2\(60\)ez13:*:*:*:*:*:*:*
cisco ios 12.2\(60\)ez14 cpe:2.3:o:cisco:ios:12.2\(60\)ez14:*:*:*:*:*:*:*
cisco ios 12.4\(22\)md cpe:2.3:o:cisco:ios:12.4\(22\)md:*:*:*:*:*:*:*
cisco ios 12.4\(22\)md1 cpe:2.3:o:cisco:ios:12.4\(22\)md1:*:*:*:*:*:*:*
cisco ios 12.4\(22\)md2 cpe:2.3:o:cisco:ios:12.4\(22\)md2:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda cpe:2.3:o:cisco:ios:12.4\(22\)mda:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda1 cpe:2.3:o:cisco:ios:12.4\(22\)mda1:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda2 cpe:2.3:o:cisco:ios:12.4\(22\)mda2:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda3 cpe:2.3:o:cisco:ios:12.4\(22\)mda3:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda4 cpe:2.3:o:cisco:ios:12.4\(22\)mda4:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda5 cpe:2.3:o:cisco:ios:12.4\(22\)mda5:*:*:*:*:*:*:*
cisco ios 12.4\(22\)mda6 cpe:2.3:o:cisco:ios:12.4\(22\)mda6:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t cpe:2.3:o:cisco:ios:12.4\(22\)t:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t1 cpe:2.3:o:cisco:ios:12.4\(22\)t1:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t2 cpe:2.3:o:cisco:ios:12.4\(22\)t2:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t3 cpe:2.3:o:cisco:ios:12.4\(22\)t3:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t4 cpe:2.3:o:cisco:ios:12.4\(22\)t4:*:*:*:*:*:*:*
cisco ios 12.4\(22\)t5 cpe:2.3:o:cisco:ios:12.4\(22\)t5:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr1 cpe:2.3:o:cisco:ios:12.4\(22\)xr1:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr2 cpe:2.3:o:cisco:ios:12.4\(22\)xr2:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr3 cpe:2.3:o:cisco:ios:12.4\(22\)xr3:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr4 cpe:2.3:o:cisco:ios:12.4\(22\)xr4:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr5 cpe:2.3:o:cisco:ios:12.4\(22\)xr5:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr6 cpe:2.3:o:cisco:ios:12.4\(22\)xr6:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr7 cpe:2.3:o:cisco:ios:12.4\(22\)xr7:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr8 cpe:2.3:o:cisco:ios:12.4\(22\)xr8:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr9 cpe:2.3:o:cisco:ios:12.4\(22\)xr9:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr10 cpe:2.3:o:cisco:ios:12.4\(22\)xr10:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr11 cpe:2.3:o:cisco:ios:12.4\(22\)xr11:*:*:*:*:*:*:*
cisco ios 12.4\(22\)xr12 cpe:2.3:o:cisco:ios:12.4\(22\)xr12:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md cpe:2.3:o:cisco:ios:12.4\(24\)md:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md1 cpe:2.3:o:cisco:ios:12.4\(24\)md1:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md2 cpe:2.3:o:cisco:ios:12.4\(24\)md2:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md3 cpe:2.3:o:cisco:ios:12.4\(24\)md3:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md4 cpe:2.3:o:cisco:ios:12.4\(24\)md4:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md5 cpe:2.3:o:cisco:ios:12.4\(24\)md5:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md6 cpe:2.3:o:cisco:ios:12.4\(24\)md6:*:*:*:*:*:*:*
cisco ios 12.4\(24\)md7 cpe:2.3:o:cisco:ios:12.4\(24\)md7:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda cpe:2.3:o:cisco:ios:12.4\(24\)mda:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda1 cpe:2.3:o:cisco:ios:12.4\(24\)mda1:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda2 cpe:2.3:o:cisco:ios:12.4\(24\)mda2:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda3 cpe:2.3:o:cisco:ios:12.4\(24\)mda3:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda4 cpe:2.3:o:cisco:ios:12.4\(24\)mda4:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda5 cpe:2.3:o:cisco:ios:12.4\(24\)mda5:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda6 cpe:2.3:o:cisco:ios:12.4\(24\)mda6:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda7 cpe:2.3:o:cisco:ios:12.4\(24\)mda7:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda8 cpe:2.3:o:cisco:ios:12.4\(24\)mda8:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda9 cpe:2.3:o:cisco:ios:12.4\(24\)mda9:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda10 cpe:2.3:o:cisco:ios:12.4\(24\)mda10:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda11 cpe:2.3:o:cisco:ios:12.4\(24\)mda11:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda12 cpe:2.3:o:cisco:ios:12.4\(24\)mda12:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mda13 cpe:2.3:o:cisco:ios:12.4\(24\)mda13:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb cpe:2.3:o:cisco:ios:12.4\(24\)mdb:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb1 cpe:2.3:o:cisco:ios:12.4\(24\)mdb1:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb3 cpe:2.3:o:cisco:ios:12.4\(24\)mdb3:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb4 cpe:2.3:o:cisco:ios:12.4\(24\)mdb4:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb5 cpe:2.3:o:cisco:ios:12.4\(24\)mdb5:*:*:*:*:*:*:*
cisco ios 12.4\(24\)mdb5a cpe:2.3:o:cisco:ios:12.4\(24\)mdb5a:*:*:*:*:*:*:*

References for CVE-2020-3200

cvelogic Threat Intelligence