libwebp: out-of-bounds read in ChunkAssignData() in mux/muxinternal.c
Published May 21, 2021
9.1
CRITICALCVSS 3.1
EPSS 2.30%
Description
A flaw was found in libwebp in versions before 1.0.1. An out-of-bounds read was found in function ChunkAssignData. The highest threat from this vulnerability is to data confidentiality and to the service availability.
Affected products
- Vendor n/a Product Libwebp Defaultn/a
- Version libwebp 1.0.1StatusaffectedConstraints-
- 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 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n/a | Libwebp | n/a |
|
Configuration 1
- < 1.0.1
Configuration 2
- 8.0
Configuration 3
- n/a
Configuration 4
- 9.0
- 10.0
No data.
Red Hat Enterprise Linux 8
libwebp-0:1.0.0-5.el8
Fixed · RHSA-2021:4231
Red Hat Enterprise Linux 7
firefox
Out of support scope
Red Hat Enterprise Linux 7
libwebp
Out of support scope
Red Hat Enterprise Linux 7
qt5-qtimageformats
Out of support scope
Red Hat Enterprise Linux 7
thunderbird
Out of support scope
Red Hat Enterprise Linux 8
firefox
Not affected
Red Hat Enterprise Linux 8
thunderbird
Not affected
Red Hat Enterprise Linux 9
libwebp
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | libwebp-0:1.0.0-5.el8 | Fixed | RHSA-2021:4231 |
| Red Hat Enterprise Linux 7 | firefox | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | libwebp | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | qt5-qtimageformats | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Out of support scope | n/a |
| Red Hat Enterprise Linux 8 | firefox | Not affected | n/a |
| Red Hat Enterprise Linux 8 | thunderbird | Not affected | n/a |
| Red Hat Enterprise Linux 9 | libwebp | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This issue did not affect the versions of Firefox and Thunderbird as shipped with Red Hat Enterprise Linux 7, and 8 as they embed the fixed version of libwebp.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/C:P/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 (24 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 2.30% (0.02302) | 82.69th | v5 (v2026.06.15) |
| Jun 15, 2026 | 2.30% (0.02302) | 81.00th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.19% (0.00189) | 40.96th | v4 (v2025.03.14) |
| Nov 18, 2025 | 1.42% (0.01420) | 78.92th | v4 (v2025.03.14) |
| Mar 30, 2025 | 0.27% (0.00269) | 47.44th | v4 (v2025.03.14) |
| Mar 29, 2025 | 1.67% (0.01673) | 70.68th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.27% (0.00269) | 48.34th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.42% (0.00422) | 75.07th | v3 (v2023.03.01) |
| Mar 1, 2024 | 0.42% (0.00422) | 73.69th | v3 (v2023.03.01) |
| Feb 4, 2024 | 0.42% (0.00422) | 71.69th | v3 (v2023.03.01) |
| Dec 26, 2023 | 0.30% (0.00298) | 66.13th | v3 (v2023.03.01) |
| Nov 30, 2023 | 0.29% (0.00289) | 65.51th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.20% (0.00203) | 56.49th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.11% (0.01108) | 55.18th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.11% (0.01108) | 51.54th | v2 (v2022.01.01) |
| Feb 4, 2022 | 21.11% (0.21114) | 94.13th | v2 (v2022.01.01) |
| Feb 3, 2022 | 1.16% (0.01163) | 29.82th | v1 |
| Dec 2, 2021 | 0.26% (0.00261) | 5.47th | v1 |
| Dec 1, 2021 | 1.76% (0.01762) | 74.71th | v5 (v2026.06.15) |
| Jul 22, 2021 | 1.32% (0.01324) | 0.00th | v1 |
| Jun 12, 2021 | 1.10% (0.01105) | 0.00th | v1 |
| Jun 8, 2021 | 0.88% (0.00884) | 0.00th | v1 |
| Jun 6, 2021 | 0.66% (0.00663) | 0.00th | v1 |
| May 22, 2021 | 0.44% (0.00442) | 0.00th | v1 |
References (10)
- http://seclists.org/fulldisclosure/2021/Jul/54 mailing-listx_refsource_FULLDISCMailing ListThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2020-36331 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1956856 x_refsource_MISCIssue TrackingPatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00005.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00006.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2020-36331
- https://security.netapp.com/advisory/ntap-20211112-0001/ x_refsource_CONFIRMThird Party Advisory
- https://support.apple.com/kb/HT212601 x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2020-36331
- https://www.debian.org/security/2021/dsa-4930 vendor-advisoryx_refsource_DEBIANMailing ListThird Party Advisory
| Link | Providers | Tags |
|---|---|---|
| http://seclists.org/fulldisclosure/2021/Jul/54 | mailing-listx_refsource_FULLDISCMailing ListThird Party Advisory | |
| https://access.redhat.com/security/cve/CVE-2020-36331 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1956856 | x_refsource_MISCIssue TrackingPatchThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2021/06/msg00005.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://lists.debian.org/debian-lts-announce/2021/06/msg00006.html | mailing-listx_refsource_MLISTMailing ListThird Party Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2020-36331 | ||
| https://security.netapp.com/advisory/ntap-20211112-0001/ | x_refsource_CONFIRMThird Party Advisory | |
| https://support.apple.com/kb/HT212601 | x_refsource_CONFIRMThird Party Advisory | |
| https://www.cve.org/CVERecord?id=CVE-2020-36331 | ||
| https://www.debian.org/security/2021/dsa-4930 | vendor-advisoryx_refsource_DEBIANMailing ListThird Party Advisory |
Change history (0)
No recorded changes yet.