expat: Inifinite loop due to invalid XML in external entity
Published Jul 25, 2017
7.5
HIGHCVSS 3.1
EPSS 8.74%
Description
XML External Entity vulnerability in libexpat 2.2.0 and earlier (Expat XML Parser Library) allows attackers to put the parser in an infinite loop using a malformed external entity definition from an external DTD.
Affected products
No data.
Configuration 1
- ≤ 2.2.0
Configuration 2
Configuration 3
- 8.0
- 9.0
- 10.0
No data.
Red Hat Enterprise Linux 5
expat
Will not fix
Red Hat Enterprise Linux 5
firefox
Will not fix
Red Hat Enterprise Linux 5
thunderbird
Will not fix
Red Hat Enterprise Linux 5
xmlrpc-c
Will not fix
Red Hat Enterprise Linux 5
xulrunner
Will not fix
Red Hat Enterprise Linux 6
compat-expat1
Will not fix
Red Hat Enterprise Linux 6
firefox
Will not fix
Red Hat Enterprise Linux 6
thunderbird
Will not fix
Red Hat Enterprise Linux 6
xulrunner
Will not fix
Red Hat Enterprise Linux 7
expat
Will not fix
Red Hat Enterprise Linux 7
firefox
Will not fix
Red Hat Enterprise Linux 7
thunderbird
Will not fix
Red Hat Enterprise Linux 7
xulrunner
Will not fix
Red Hat Enterprise Virtualization 3
mingw-virt-viewer
Will not fix
Red Hat JBoss Enterprise Application Platform 6
httpd
Will not fix
Red Hat JBoss Enterprise Web Server 2
httpd
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | expat | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | xmlrpc-c | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | xulrunner | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | compat-expat1 | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | xulrunner | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | expat | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | firefox | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | thunderbird | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | xulrunner | Will not fix | n/a |
| Red Hat Enterprise Virtualization 3 | mingw-virt-viewer | Will not fix | n/a |
| Red Hat JBoss Enterprise Application Platform 6 | httpd | Will not fix | n/a |
| Red Hat JBoss Enterprise Web Server 2 | httpd | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat mitigation
Do not parse untrusted arbitrary XML data using the expat package.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/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 v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (21 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 8.74% (0.08739) | 95.00th | v5 (v2026.06.15) |
| Jun 15, 2026 | 8.74% (0.08739) | 94.46th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.18% (0.00185) | 40.51th | v4 (v2025.03.14) |
| Nov 18, 2025 | 6.06% (0.06064) | 89.82th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.37% (0.00373) | 56.88th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.30% (0.00304) | 70.53th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.30% (0.00304) | 68.87th | v3 (v2023.03.01) |
| Oct 29, 2023 | 0.30% (0.00304) | 66.30th | v3 (v2023.03.01) |
| Sep 20, 2023 | 0.43% (0.00431) | 71.48th | v3 (v2023.03.01) |
| May 8, 2023 | 0.38% (0.00383) | 68.97th | v3 (v2023.03.01) |
| Mar 14, 2023 | 0.50% (0.00495) | 72.52th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.86% (0.00859) | 79.75th | v3 (v2023.03.01) |
| Mar 6, 2023 | 2.69% (0.02686) | 82.85th | v2 (v2022.01.01) |
| Apr 1, 2022 | 2.69% (0.02686) | 81.17th | v2 (v2022.01.01) |
| Feb 4, 2022 | 2.69% (0.02686) | 62.66th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.88% (0.02880) | 63.65th | v1 |
| Jan 6, 2022 | 2.88% (0.02880) | 63.31th | v1 |
| Sep 1, 2021 | 2.88% (0.02880) | 80.71th | v1 |
| Jun 30, 2021 | 2.88% (0.02880) | 0.00th | v1 |
| Jun 29, 2021 | 2.68% (0.02678) | 0.00th | v1 |
| Apr 14, 2021 | 2.48% (0.02476) | 0.00th | v1 |
References (17)
- http://www.debian.org/security/2017/dsa-3898 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- http://www.openwall.com/lists/oss-security/2017/06/17/7 mailing-listx_refsource_MLISTMailing ListVDB Entry
- http://www.securityfocus.com/bid/99276 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1039427 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2017-9233 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1462729 Issue Tracking
- https://github.com/libexpat/libexpat/blob/master/expat/Changes x_refsource_CONFIRMRelease NotesThird Party Advisory
- https://libexpat.github.io/doc/cve-2017-9233/ x_refsource_CONFIRMExploitTechnical DescriptionVendor Advisory
- https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E mailing-listx_refsource_MLIST
- https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E mailing-listx_refsource_MLIST
- https://nvd.nist.gov/vuln/detail/CVE-2017-9233
- https://support.apple.com/HT208112 x_refsource_CONFIRMThird Party Advisory
- https://support.apple.com/HT208113 x_refsource_CONFIRMThird Party Advisory
- https://support.apple.com/HT208115 x_refsource_CONFIRMThird Party Advisory
- https://support.apple.com/HT208144 x_refsource_CONFIRMThird Party Advisory
- https://support.f5.com/csp/article/K03244804 x_refsource_CONFIRMThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2017-9233
Change history (0)
No recorded changes yet.