The CAPTCHA functionality in php-Nuke 6.0 through 7.9 uses fixed challenge/response pairs that only vary once per day based on the User Agent (HTTP_USER_AGENT), which allows remote attackers to bypass CAPTCHA controls by fixing the User Agent, performing a valid challenge/response, then replaying that pair in the random_num and gfx_check parameters
Published Feb 21, 2006
7.5
HIGHCVSS 2.0
EPSS 3.00%
Description
The CAPTCHA functionality in php-Nuke 6.0 through 7.9 uses fixed challenge/response pairs that only vary once per day based on the User Agent (HTTP_USER_AGENT), which allows remote attackers to bypass CAPTCHA controls by fixing the User Agent, performing a valid challenge/response, then replaying that pair in the random_num and gfx_check parameters.
Affected products
No data.
- 6.0
- 6.5
- 6.5_beta1
- 6.5_final
- 6.5_rc1
- 6.5_rc2
- 6.5_rc3
- 6.6
- 6.7
- 6.9
- 7.0
- 7.0_final
- 7.1
- 7.2
- 7.3
- 7.4
- 7.5
- 7.6
- 7.7
- 7.8
- 7.9
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:P/I:P/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 2, 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 (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 3.00% (0.02996) | 86.89th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.93% (0.02927) | 85.22th | v5 (v2026.06.15) |
| Mar 17, 2025 | 1.76% (0.01759) | 81.35th | v4 (v2025.03.14) |
| Dec 12, 2024 | 2.28% (0.02284) | 90.05th | v3 (v2023.03.01) |
| Jun 12, 2024 | 2.28% (0.02284) | 89.67th | v3 (v2023.03.01) |
| May 27, 2023 | 3.20% (0.03202) | 89.76th | v3 (v2023.03.01) |
| Mar 11, 2023 | 3.59% (0.03588) | 90.20th | v3 (v2023.03.01) |
| Mar 7, 2023 | 3.64% (0.03643) | 90.25th | v3 (v2023.03.01) |
| Mar 6, 2023 | 4.48% (0.04482) | 88.77th | v2 (v2022.01.01) |
| Apr 1, 2022 | 4.48% (0.04482) | 87.66th | v2 (v2022.01.01) |
| Feb 4, 2022 | 4.48% (0.04482) | 71.45th | v2 (v2022.01.01) |
No CWE recorded.
References (5)
- http://secunia.com/advisories/18936 third-party-advisoryx_refsource_SECUNIA
- http://securityreason.com/securityalert/455 third-party-advisoryx_refsource_SREASON
- http://www.securityfocus.com/archive/1/425394/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/bid/16722 vdb-entryx_refsource_BIDExploit
- http://www.waraxe.us/advisory-45.html x_refsource_MISCExploitVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://secunia.com/advisories/18936 | third-party-advisoryx_refsource_SECUNIA | |
| http://securityreason.com/securityalert/455 | third-party-advisoryx_refsource_SREASON | |
| http://www.securityfocus.com/archive/1/425394/100/0/threaded | mailing-listx_refsource_BUGTRAQ | |
| http://www.securityfocus.com/bid/16722 | vdb-entryx_refsource_BIDExploit | |
| http://www.waraxe.us/advisory-45.html | x_refsource_MISCExploitVendor Advisory |
Change history (0)
No recorded changes yet.