A certain pseudo-random number generator (PRNG) algorithm that uses ADD with 0 random hops (aka "Algorithm A0"), as used in OpenBSD 3.5 through 4.2 and NetBSD 1.6.2 through 4.0, allows remote attackers to guess sensitive values such as (1) DNS transaction IDs or (2) IP fragmentation IDs by observing a sequence of previously generated values
Published Mar 4, 2008
6.8
MEDIUMCVSS 2.0
EPSS 1.42%
Description
A certain pseudo-random number generator (PRNG) algorithm that uses ADD with 0 random hops (aka "Algorithm A0"), as used in OpenBSD 3.5 through 4.2 and NetBSD 1.6.2 through 4.0, allows remote attackers to guess sensitive values such as (1) DNS transaction IDs or (2) IP fragmentation IDs by observing a sequence of previously generated values. NOTE: this issue can be leveraged for attacks such as DNS cache poisoning, injection into TCP packets, and OS fingerprinting.
Affected products
No data.
Running on/with
- 10.0
- 10.0.1
- 10.0.2
- 10.0.3
- 10.0.4
- 10.1
- 10.1.1
- 10.1.2
- 10.1.3
- 10.1.4
- 10.1.5
- 10.2
- 10.2.1
- 10.2.2
- 10.2.3
- 10.2.4
- 10.2.5
- 10.2.6
- 10.2.7
- 10.2.8
- 10.3
- 10.3.1
- 10.3.2
- 10.3.3
- 10.3.4
- 10.3.5
- 10.3.6
- 10.3.7
- 10.3.8
- 10.3.9
- 10.4
- 10.4.1
- 10.4.2
- 10.4.3
- 10.4.4
- 10.4.5
- 10.4.6
- 10.4.7
- 10.4.8
- 10.4.9
- 10.4.10
- 10.4.11
- 10.5
- 10.5.1
- 10.0
- 10.1
- 10.1.1
- 10.1.2
- 10.1.3
- 10.1.4
- 10.1.5
- 10.2
- 10.2.1
- 10.2.2
- 10.2.3
- 10.2.4
- 10.2.5
- 10.2.6
- 10.2.7
- 10.2.8
- 10.3
- 10.3.1
- 10.3.2
- 10.3.3
- 10.3.4
- 10.3.5
- 10.3.6
- 10.3.7
- 10.3.8
- 10.3.9
- 10.4
- 10.4.1
- 10.4.2
- 10.4.3
- 10.4.4
- 10.4.5
- 10.4.6
- 10.4.7
- 10.4.8
- 10.4.9
- 10.4.10
- 10.4.11
- 10.5
- 1.0
- 1.1
- 1.2
- 1.10.1
- 4.4
- 4.4
- 4.4
- 4.4
- 4.5
- 4.5
- 4.5
- 4.5
- 4.5
- 4.6
- 4.6
- 4.6
- 4.6
- 4.6
- 4.6.2
- 4.7
- 4.7
- 4.7
- 4.7
- 4.7
- 4.8
- 4.8
- 4.8
- 4.8_prerelease
- 4.9
- 4.9
- 4.9_prerelease
- 4.10
- 4.10
- 4.10
- 4.10
- 4.10_prerelease
- 4.11
- 4.11
- 4.11
- 4.11_p20_release
- 4.11_release
- 5.0
- 5.0
- 5.0
- 5.0
- 5.1
- 5.1
- 5.1
- 5.1
- 5.1
- 5.2
- 5.2.1
- 5.2.1
- 5.3
- 5.3
- 5.3
- 5.3
- 5.4
- 5.4
- 5.4
- 5.5_release
- 5.5_stable
- 6.0
- 6.0
- 6.0
- 6.0_p5_release
- 6.1
- 6.1
- 6.1
- 6.1
- 6.2
- 6.2
- 6.2_releng
- 6.3
- 6.3_releng
- 7.0
- 7.0_beta4
- 7.0_releng
- 1.6.2
- 2.0
- 2.0.1
- 2.0.2
- 2.0.3
- 2.0.4
- 2.1
- 2.1.1
- 3.0.1
- 3.0.2
- 3.1
- 3.1
- 3.1
- 4.0
- 4.0
- 4.0
- 2.6
- 2.7
- 2.8
- 2.9
- 3.0
- 3.1
- 3.2
- 3.3
- 3.4
- 3.5
- 3.6
- 3.7
- 3.8
- 3.9
- 4.0
- 4.1
- 4.2
- 10.0.3
- 1.0
- 9.1
- 3.0
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: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 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 (11 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.42% (0.01424) | 71.94th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.42% (0.01424) | 69.33th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.97% (0.00973) | 75.10th | v4 (v2025.03.14) |
| Feb 13, 2025 | 3.08% (0.03076) | 90.97th | v3 (v2023.03.01) |
| Dec 12, 2024 | 1.94% (0.01945) | 89.16th | v3 (v2023.03.01) |
| Mar 10, 2024 | 2.00% (0.01996) | 88.51th | v3 (v2023.03.01) |
| Mar 7, 2023 | 1.85% (0.01847) | 86.45th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.32% (0.01319) | 71.27th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.32% (0.01319) | 71.23th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.32% (0.01319) | 69.22th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.32% (0.01319) | 44.98th | v2 (v2022.01.01) |
No CWE recorded.
References (7)
- http://secunia.com/advisories/28819 third-party-advisoryx_refsource_SECUNIAVendor Advisory
- http://www.securiteam.com/securityreviews/5PP0H0UNGW.html x_refsource_MISC
- http://www.securityfocus.com/archive/1/487658 mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/bid/27647 vdb-entryx_refsource_BID
- http://www.trusteer.com/docs/OpenBSD_DNS_Cache_Poisoning_and_Multiple_OS_Predictable_IP_ID_Vulnerability.pdf x_refsource_MISC
- https://exchange.xforce.ibmcloud.com/vulnerabilities/40329 vdb-entryx_refsource_XF
- https://exchange.xforce.ibmcloud.com/vulnerabilities/41157 vdb-entryx_refsource_XF
| Link | Providers | Tags |
|---|---|---|
| http://secunia.com/advisories/28819 | third-party-advisoryx_refsource_SECUNIAVendor Advisory | |
| http://www.securiteam.com/securityreviews/5PP0H0UNGW.html | x_refsource_MISC | |
| http://www.securityfocus.com/archive/1/487658 | mailing-listx_refsource_BUGTRAQ | |
| http://www.securityfocus.com/bid/27647 | vdb-entryx_refsource_BID | |
| http://www.trusteer.com/docs/OpenBSD_DNS_Cache_Poisoning_and_Multiple_OS_Predictable_IP_ID_Vulnerability.pdf | x_refsource_MISC | |
| https://exchange.xforce.ibmcloud.com/vulnerabilities/40329 | vdb-entryx_refsource_XF | |
| https://exchange.xforce.ibmcloud.com/vulnerabilities/41157 | vdb-entryx_refsource_XF |
Change history (0)
No recorded changes yet.