The layout engine in Mozilla Firefox before 4.0, Thunderbird before 3.3, and SeaMonkey before 2.1 executes different code for visited and unvisited links during the processing of Cascading Style Sheets (CSS) token sequences, which makes it easier for remote attackers to obtain sensitive information about visited web pages via a timing attack
Published Dec 7, 2011
4.3
MEDIUMCVSS 2.0
EPSS 0.64%
Description
The layout engine in Mozilla Firefox before 4.0, Thunderbird before 3.3, and SeaMonkey before 2.1 executes different code for visited and unvisited links during the processing of Cascading Style Sheets (CSS) token sequences, which makes it easier for remote attackers to obtain sensitive information about visited web pages via a timing attack.
Affected products
No data.
Configuration 1
- ≤ 3.6.24
- 3.0
- 3.0.1
- 3.0.2
- 3.0.3
- 3.0.4
- 3.0.5
- 3.0.6
- 3.0.7
- 3.0.8
- 3.0.9
- 3.0.10
- 3.0.11
- 3.0.12
- 3.0.13
- 3.0.14
- 3.0.15
- 3.0.16
- 3.0.17
- 3.5
- 3.5.1
- 3.5.2
- 3.5.3
- 3.5.4
- 3.5.5
- 3.5.6
- 3.5.7
- 3.5.8
- 3.5.9
- 3.5.10
- 3.5.11
- 3.5.12
- 3.5.13
- 3.5.14
- 3.5.15
- 3.6
- 3.6.1
- 3.6.2
- 3.6.3
- 3.6.4
- 3.6.6
- 3.6.7
- 3.6.8
- 3.6.9
- 3.6.10
- 3.6.11
- 3.6.12
- 3.6.13
- 3.6.14
- 3.6.15
- 3.6.16
- 3.6.17
- 3.6.18
- 3.6.19
- 3.6.20
- 3.6.21
- 3.6.22
- 3.6.23
Configuration 2
- ≤ 3.1.16
- 3.0
- 3.0.1
- 3.0.2
- 3.0.3
- 3.0.4
- 3.0.5
- 3.0.6
- 3.0.7
- 3.0.8
- 3.0.9
- 3.0.10
- 3.0.11
- 3.1
- 3.1.1
- 3.1.2
- 3.1.3
- 3.1.4
- 3.1.5
- 3.1.6
- 3.1.7
- 3.1.8
- 3.1.9
- 3.1.10
- 3.1.11
- 3.1.12
- 3.1.13
- 3.1.14
- 3.1.15
Configuration 3
- ≤ 2.1
- 1.0
- 1.0
- 1.0
- 1.0.1
- 1.0.2
- 1.0.3
- 1.0.4
- 1.0.5
- 1.0.6
- 1.0.7
- 1.0.8
- 1.0.9
- 1.1
- 1.1
- 1.1
- 1.1.1
- 1.1.2
- 1.1.3
- 1.1.4
- 1.1.5
- 1.1.6
- 1.1.7
- 1.1.8
- 1.1.9
- 1.1.10
- 1.1.11
- 1.1.12
- 1.1.13
- 1.1.14
- 1.1.15
- 1.1.16
- 1.1.17
- 1.1.18
- 1.1.19
- 1.5.0.8
- 1.5.0.9
- 1.5.0.10
- 2.0
- 2.0
- 2.0
- 2.0
- 2.0
- 2.0
- 2.0
- 2.0
- 2.0.1
- 2.0.2
- 2.0.3
- 2.0.4
- 2.0.5
- 2.0.6
- 2.0.7
- 2.0.8
- 2.0.9
- 2.0.10
- 2.0.11
- 2.0.12
- 2.0.13
- 2.0.14
- 2.0a1
- 2.1
- 2.1
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: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
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 | 0.64% (0.00644) | 48.99th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.70% (0.00702) | 48.21th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.18% (0.00178) | 37.10th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.27% (0.00269) | 68.69th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.27% (0.00269) | 66.87th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.27% (0.00269) | 62.63th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.05% (0.01055) | 52.13th | v2 (v2022.01.01) |
| Sep 17, 2022 | 1.05% (0.01055) | 50.47th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.05% (0.01055) | 48.43th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.05% (0.01055) | 27.52th | v2 (v2022.01.01) |
References (2)
- http://blog.mozilla.com/security/2010/03/31/plugging-the-css-history-leak/ x_refsource_CONFIRM
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14456 vdb-entrysignaturex_refsource_OVAL
| Link | Providers | Tags |
|---|---|---|
| http://blog.mozilla.com/security/2010/03/31/plugging-the-css-history-leak/ | x_refsource_CONFIRM | |
| https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14456 | vdb-entrysignaturex_refsource_OVAL |
Change history (0)
No recorded changes yet.