Proxy Auto-Config (PAC) files can specify a JavaScript function called for all URL requests with the full URL path which exposes more information than would be sent to the proxy itself in the case of HTTPS
Published Jun 11, 2018
5.9
MEDIUMCVSS 3.0
EPSS 1.50%
Description
Proxy Auto-Config (PAC) files can specify a JavaScript function called for all URL requests with the full URL path which exposes more information than would be sent to the proxy itself in the case of HTTPS. Normally the Proxy Auto-Config file is specified by the user or machine owner and presumed to be non-malicious, but if a user has enabled Web Proxy Auto Detect (WPAD) this file can be served remotely. This vulnerability affects Firefox < 51.
Affected products
-
- Version unspecifiedStatusaffectedConstraints<51
- Version
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.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
AV:N/AC:M/Au:N/C:P/I:N/A:N
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
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (15 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.50% (0.01501) | 73.36th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.52% (0.01521) | 71.22th | v5 (v2026.06.15) |
| May 30, 2025 | 0.80% (0.00805) | 72.99th | v4 (v2025.03.14) |
| Mar 30, 2025 | 2.05% (0.02052) | 82.27th | v4 (v2025.03.14) |
| Mar 29, 2025 | 4.02% (0.04021) | 80.47th | v4 (v2025.03.14) |
| Mar 17, 2025 | 1.70% (0.01702) | 81.07th | v4 (v2025.03.14) |
| Dec 17, 2024 | 0.14% (0.00135) | 49.37th | v3 (v2023.03.01) |
| Apr 18, 2024 | 0.66% (0.00655) | 79.24th | v3 (v2023.03.01) |
| Nov 2, 2023 | 0.66% (0.00655) | 77.22th | v3 (v2023.03.01) |
| Sep 3, 2023 | 0.67% (0.00666) | 77.13th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.56% (0.00555) | 74.13th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.02% (0.01018) | 19.50th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.32% (0.01324) | 31.25th | v5 (v2026.06.15) |
| Apr 14, 2021 | 1.32% (0.01324) | 0.00th | v1 |
References (5)
- http://www.securityfocus.com/bid/95763 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1037693 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1255474 x_refsource_CONFIRMIssue TrackingPatchVendor Advisory
- https://www.contextis.com//resources/blog/leaking-https-urls-20-year-old-vulnerability/ x_refsource_MISCExploitTechnical DescriptionThird Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2017-01/ x_refsource_CONFIRMVendor Advisory
| Link | Providers | Tags |
|---|---|---|
| http://www.securityfocus.com/bid/95763 | vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry | |
| http://www.securitytracker.com/id/1037693 | vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry | |
| https://bugzilla.mozilla.org/show_bug.cgi?id=1255474 | x_refsource_CONFIRMIssue TrackingPatchVendor Advisory | |
| https://www.contextis.com//resources/blog/leaking-https-urls-20-year-old-vulnerability/ | x_refsource_MISCExploitTechnical DescriptionThird Party Advisory | |
| https://www.mozilla.org/security/advisories/mfsa2017-01/ | x_refsource_CONFIRMVendor Advisory |
Change history (0)
No recorded changes yet.