Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot
Published Jun 2, 2000
5.0
MEDIUMCVSS 2.0
EPSS 1.66%
Description
Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot.
Affected products
No data.
Configuration 1
- 11.3aa
- 12.0\(2\)
- 12.0\(2\)xc
- 12.0\(2\)xd
- 12.0\(2\)xf
- 12.0\(2\)xg
- 12.0\(3\)t2
- 12.0\(4\)
- 12.0\(4\)s
- 12.0\(4\)t
- 12.0\(5\)
- 12.0\(6\)
- 12.0\(7\)t
- ls-3
- ts-3
- vs-3
- n/a
- n/a
- n/a
- n/a
- n/a
Configuration 2
- n/a
- n/a
- n/a
- n/a
- n/a
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/C:N/I:N/A:P
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.66% (0.01657) | 75.75th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.66% (0.01657) | 73.48th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.74% (0.00739) | 71.20th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.65% (0.00646) | 79.99th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.65% (0.00646) | 78.63th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.73% (0.00725) | 77.65th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.21% (0.01213) | 66.61th | v2 (v2022.01.01) |
| Feb 17, 2023 | 1.21% (0.01213) | 66.22th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.21% (0.01213) | 64.21th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.21% (0.01213) | 40.54th | v2 (v2022.01.01) |
No CWE recorded.
References (3)
- http://www.cisco.com/warp/public/707/iostelnetopt-pub.shtml vendor-advisoryx_refsource_CISCOPatchVendor Advisory
- http://www.osvdb.org/1289 vdb-entryx_refsource_OSVDB
- http://www.securityfocus.com/bid/1123 vdb-entryx_refsource_BID
| Link | Providers | Tags |
|---|---|---|
| http://www.cisco.com/warp/public/707/iostelnetopt-pub.shtml | vendor-advisoryx_refsource_CISCOPatchVendor Advisory | |
| http://www.osvdb.org/1289 | vdb-entryx_refsource_OSVDB | |
| http://www.securityfocus.com/bid/1123 | vdb-entryx_refsource_BID |
Change history (0)
No recorded changes yet.