A race condition when discarding malformed packets can cause BIND to exit with an assertion failure
Published Oct 9, 2019
5.9
MEDIUMCVSS 3.1
EPSS 3.30%
Description
A race condition which may occur when discarding malformed packets can result in BIND exiting due to a REQUIRE assertion failure in dispatch.c. Versions affected: BIND 9.11.0 -> 9.11.7, 9.12.0 -> 9.12.4-P1, 9.14.0 -> 9.14.2. Also all releases of the BIND 9.13 development branch and version 9.15.0 of the BIND 9.15 development branch and BIND Supported Preview Edition versions 9.11.3-S1 -> 9.11.7-S1.
Affected products
-
- Version BIND 9.11.0 -> 9.11.7, 9.12.0 -> 9.12.4-P1, 9.14.0 -> 9.14.2. Also all releases of the BIND 9.13 development branch and version 9.15.0 of the BIND 9.15 development branch and BIND Supported Preview Edition versions 9.11.3-S1 -> 9.11.7-S1.StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| ISC | BIND 9 | n/a |
|
Configuration 1
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 2
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 3
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 4
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 5
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 6
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 7
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 8
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 9
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 9.2.2
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 10
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 9.2.2
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 11
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 9.2.2
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 12
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 9.2.2
- 14.0.0
- 14.1.0
- 15.0.0
Configuration 13
- ≥ 9.11.0 · ≤ 9.11.7
- ≥ 9.12.0 · ≤ 9.12.3
- ≥ 9.13.0 · ≤ 9.13.7
- ≥ 9.14.0 · ≤ 9.14.2
- ≥ 9.15.0 · ≤ 9.15.5
- 9.11.3
- 9.11.7
- 9.12.4
- 9.12.4
Configuration 14
- 3.1.1
Configuration 15
- ≥ 5.1.0 · ≤ 5.4.0
- ≥ 6.0.0 · ≤ 6.1.0
Configuration 17
- ≥ 11.5.2 · ≤ 11.5.9
- ≥ 11.6.1 · ≤ 11.6.4
- ≥ 12.1.0 · ≤ 12.1.4
- ≥ 13.1.0 · ≤ 13.1.1
- 9.2.2
- 14.0.0
- 14.1.0
- 15.0.0
No data.
Red Hat Enterprise Linux 8
bind-32:9.11.4-17.P2.el8_0.1
Fixed · RHSA-2019:1714
Red Hat Enterprise Linux 8
bind-32:9.11.4-17.P2.el8_0.1
Fixed · RHSA-2019:1714
Red Hat Enterprise Linux 5
bind
Not affected
Red Hat Enterprise Linux 5
bind97
Not affected
Red Hat Enterprise Linux 6
bind
Not affected
Red Hat Enterprise Linux 7
bind
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | bind-32:9.11.4-17.P2.el8_0.1 | Fixed | RHSA-2019:1714 |
| Red Hat Enterprise Linux 8 | bind-32:9.11.4-17.P2.el8_0.1 | Fixed | RHSA-2019:1714 |
| Red Hat Enterprise Linux 5 | bind | Not affected | n/a |
| Red Hat Enterprise Linux 5 | bind97 | Not affected | n/a |
| Red Hat Enterprise Linux 6 | bind | Not affected | n/a |
| Red Hat Enterprise Linux 7 | bind | Not affected | n/a |
No package ranges for this CVE.
Remediation
Vendor solution
Upgrade to the patched release most closely related to your current version of BIND:
BIND 9.11.8 BIND 9.12.4-P2 BIND 9.14.3 BIND 9.15.1
BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers.
BIND 9.11.8-S1
Red Hat statement
This bind flaw can be exploited by a remote attacker (AV:N). However the attack works only if the attacker could cause the bind server to perform queries on another DNS server and the other DNS server deliberately responds with malformed answers (AC:H). No other special privileges are required by the attacker (PR:L). No user interaction is required from the server side (UI:N). The attacker can cause denial of service (A:H) by causing the named process to exit with an assertion flaw. There is no affect on the Confidentiality or Integrity of the system (C:N/I:N).
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:M/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
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 (14 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.30% (0.03298) | 88.11th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.84% (0.03840) | 88.72th | v5 (v2026.06.15) |
| Mar 30, 2025 | 1.26% (0.01259) | 77.55th | v4 (v2025.03.14) |
| Mar 29, 2025 | 3.47% (0.03470) | 79.02th | v4 (v2025.03.14) |
| Jul 20, 2024 | 0.11% (0.00112) | 45.15th | v3 (v2023.03.01) |
| Nov 8, 2023 | 0.11% (0.00112) | 44.50th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.10% (0.00102) | 40.03th | v3 (v2023.03.01) |
| Mar 6, 2023 | 0.89% (0.00885) | 27.89th | v2 (v2022.01.01) |
| Apr 1, 2022 | 0.89% (0.00885) | 24.24th | v2 (v2022.01.01) |
| Feb 4, 2022 | 6.84% (0.06837) | 79.65th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.74% (0.02742) | 63.06th | v5 (v2026.06.15) |
| Jan 6, 2022 | 2.74% (0.02742) | 62.72th | v1 |
| Sep 1, 2021 | 0.62% (0.00624) | 45.04th | v1 |
| Apr 14, 2021 | 0.62% (0.00624) | 0.00th | v1 |
References (6)
- https://access.redhat.com/security/cve/CVE-2019-6471 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1721780 Issue Tracking
- https://kb.isc.org/docs/cve-2019-6471 x_refsource_CONFIRMThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2019-6471
- https://support.f5.com/csp/article/K10092301?utm_source=f5support&%3Butm_medium=RSS x_refsource_CONFIRM
- https://www.cve.org/CVERecord?id=CVE-2019-6471
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2019-6471 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1721780 | Issue Tracking | |
| https://kb.isc.org/docs/cve-2019-6471 | x_refsource_CONFIRMThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2019-6471 | ||
| https://support.f5.com/csp/article/K10092301?utm_source=f5support&%3Butm_medium=RSS | x_refsource_CONFIRM | |
| https://www.cve.org/CVERecord?id=CVE-2019-6471 |
Change history (0)
No recorded changes yet.