CVE-2021-46143
published 2022-01-06CVE-2021-46143: In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
PriorityP341high7.8CVSS 3.1
AVLACLPRNUIRSUCHIHAH
EPSS
3.79%
88.8th percentile
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
Affected
11 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | expat | < expat 2.4.3-1 (bookworm) | expat 2.4.3-1 (bookworm) |
| debian | libxmltok | < expat 2.4.3-1 (bookworm) | expat 2.4.3-1 (bookworm) |
| libexpat_project | libexpat | < 2.4.3 | 2.4.3 |
| msrc | cbl2_expat_2.4.3-1_on_cbl_mariner_2.0 | — | — |
| msrc | cm1_expat_2.4.3-1_on_cbl_mariner_1.0 | — | — |
| netapp | hci_baseboard_management_controller | — | — |
| netapp | hci_baseboard_management_controller | — | — |
| netapp | hci_baseboard_management_controller | — | — |
| siemens | sinema_remote_connect_server | < 3.1 | 3.1 |
| tenable | nessus | < 8.15.3 | 8.15.3 |
| tenable | nessus | >= 10.0.0 < 10.1.1 | 10.1.1 |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.06.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian8.1HIGH
vendor_redhat8.1HIGH
vendor_msrc7.8HIGH
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
OSV
mame vulnerabilities
osv·2025-12-04·CVSS 8.8
CVE-2018-16981 [HIGH] mame vulnerabilities
mame vulnerabilities
It was discovered that the stb library, included in MAME, had a heap-based
buffer overflow. An attacker could possibly use this issue to crash the
program or execute arbitrary code. (CVE-2018-16981)
It was discovered that the tinyexr library, included in MAME, had a heap-
based buffer over-read in the function DecodePixelData. An attacker could
possibly use this issue to expose sensitive information or crash the
program. (CVE-2022-34300)
It was discovered that the expat library, included in MAME, had an
integer-overflow in the function doProlog. An attacker could possibly use
this issue to crash the program or execute arbitrary code.
(CVE-2021-46143)
OSV
libxmltok vulnerabilities
osv·2025-01-13·CVSS 6.8
CVE-2015-1283 [MEDIUM] libxmltok vulnerabilities
libxmltok vulnerabilities
It was discovered that Expat, contained within the xmltok library,
incorrectly handled malformed XML data. If a user or application were
tricked into opening a crafted XML file, an attacker could cause a denial
of service, or possibly execute arbitrary code. (CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2019-15903)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled XML data containing a large number of colons, which
could lead to excessive resource consumption. If a user or application
were tricked into opening a crafted XML file, an attacker could possibly
use this issue to cause a denial of service. (CVE-2018-20843)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled certain input, whi
OSV
libxmltok vulnerabilities
osv·2022-07-19·CVSS 5.0
CVE-2012-1148 [MEDIUM] libxmltok vulnerabilities
libxmltok vulnerabilities
Tim Boddy, Gustavo Grieco and others discovered that Expat, that is
integrated in xmltok library, incorrectly handled certain files.
An attacker could possibly use these issues to cause a denial of
service, or possibly execute arbitrary code. These issues were only
addressed in Ubuntu 16.04 ESM. (CVE-2012-1148, CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2018-20843, CVE-2019-15903,
CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824,
CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)
It was discovered that Expat, that is integrated in xmltok library,
incorrectly handled encoding validation of certain files. An attacker
could possibly use this issue to cause a denial of service, or
possibly execute arbitrary code. (CVE-2022-25235)
It was discovered
GHSA
GHSA-j6g2-cvhq-p8xr: In doProlog in xmlparse
ghsa_unreviewed·2022-02-10
CVE-2021-46143 [HIGH] CWE-190 GHSA-j6g2-cvhq-p8xr: In doProlog in xmlparse
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
OSV
CVE-2021-46143: In doProlog in xmlparse
osv·2022-01-06·CVSS 7.8
CVE-2021-46143 [HIGH] CVE-2021-46143: In doProlog in xmlparse
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
Ubuntu
MAME vulnerabilities
vendor_ubuntu·2025-12-04·CVSS 8.8
CVE-2021-46143 [HIGH] MAME vulnerabilities
Title: MAME vulnerabilities
Summary: Several security issues were fixed in MAME.
It was discovered that the stb library, included in MAME, had a heap-based
buffer overflow. An attacker could possibly use this issue to crash the
program or execute arbitrary code. (CVE-2018-16981)
It was discovered that the tinyexr library, included in MAME, had a heap-
based buffer over-read in the function DecodePixelData. An attacker could
possibly use this issue to expose sensitive information or crash the
program. (CVE-2022-34300)
It was discovered that the expat library, included in MAME, had an
integer-overflow in the function doProlog. An attacker could possibly use
this issue to crash the program or execute arbitrary code.
(CVE-2021-46143)
Instructions: In general, a standard system update will
Ubuntu
xmltok library vulnerabilities
vendor_ubuntu·2025-01-13·CVSS 6.8
CVE-2019-15903 [MEDIUM] xmltok library vulnerabilities
Title: xmltok library vulnerabilities
Summary: Several security issues were fixed in libxmltok.
It was discovered that Expat, contained within the xmltok library,
incorrectly handled malformed XML data. If a user or application were
tricked into opening a crafted XML file, an attacker could cause a denial
of service, or possibly execute arbitrary code. (CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2019-15903)
It was discovered that Expat, contained within the xmltok library,
incorrectly handled XML data containing a large number of colons, which
could lead to excessive resource consumption. If a user or application
were tricked into opening a crafted XML file, an attacker could possibly
use this issue to cause a denial of service. (CVE-2018-20843)
It was discovered that Expat, cont
CISA ICS
Hitachi Energy AFS65x, AFF66x, AFS67x, and AFR67x Series Products
cisa_ics·2023-10-05·CVSS 8.8
[HIGH] Hitachi Energy AFS65x, AFF66x, AFS67x, and AFR67x Series Products
ICS Advisory
##
Hitachi Energy AFS65x, AFF66x, AFS67x, and AFR67x Series Products
Release DateOctober 05, 2023
Alert CodeICSA-23-278-01
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Hitachi Energy
- Equipment: AFS65x, AFF66x, AFS67x, AFR67x Series
- Vulnerabilities: Incorrect Calculation, Integer Overflow or Wraparound, Improper Encoding or Escaping of Output, Exposure of Resource to Wrong Sphere
## 2. RISK EVALUATION
Successful exploitation of these vulnerabilities by an attacker could have a high impact on availability, integrity, and confidentiality of the targeted devices.
## 3. TECHNICAL DETAILS
## 3.1 AFFECTED PRODUCTS
The following Hitachi Energy products and versions are affecte
Ubuntu
xmltok library vulnerabilities
vendor_ubuntu·2022-07-19·CVSS 5.0
CVE-2021-46143 [MEDIUM] xmltok library vulnerabilities
Title: xmltok library vulnerabilities
Summary: Several security issues were fixed in libxmltok.
Tim Boddy, Gustavo Grieco and others discovered that Expat, that is
integrated in xmltok library, incorrectly handled certain files.
An attacker could possibly use these issues to cause a denial of
service, or possibly execute arbitrary code. These issues were only
addressed in Ubuntu 16.04 ESM. (CVE-2012-1148, CVE-2015-1283,
CVE-2016-0718, CVE-2016-4472, CVE-2018-20843, CVE-2019-15903,
CVE-2021-46143, CVE-2022-22822, CVE-2022-22823, CVE-2022-22824,
CVE-2022-22825, CVE-2022-22826, CVE-2022-22827)
It was discovered that Expat, that is integrated in xmltok library,
incorrectly handled encoding validation of certain files. An attacker
could possibly use this issue to cause a denial of service, o
CISA ICS
Siemens SINEMA Remote Connect Server
cisa_ics·2022-06-16·CVSS 3.7
[LOW] Siemens SINEMA Remote Connect Server
## Archived Content In an effort to keep CISA.gov current, the archive contains outdated information that may not reflect current policy or programs.
ICS Advisory
##
Siemens SINEMA Remote Connect Server
Last RevisedJune 16, 2022
Alert CodeICSA-22-167-17
## 1. EXECUTIVE SUMMARY
- CVSS v3 9.8
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: SINEMA Remote Connect Server
- Vulnerabilities: Multiple
## 2. RISK EVALUATION
Successful exploitation of these vulnerabilities could allow an attacker to escalate privileges, disclose information, or allow code execution.
## 3. TECHNICAL DETAILS
## 3.1 AFFECTED PRODUCTS
The following Siemens products are affected:
- Siemens SINEMA Remote Connect Server: All v
Ubuntu
Expat vulnerabilities
vendor_ubuntu·2022-02-21
CVE-2022-22823 Expat vulnerabilities
Title: Expat vulnerabilities
Summary: Several security issues were fixed in Expat.
It was discovered that Expat incorrectly handled certain files.
An attacker could possibly use this issue to cause a crash or
execute arbitrary code.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
expat: Integer overflow in doProlog in xmlparse.c
vendor_redhat·2022-01-15·CVSS 8.1
CVE-2021-46143 [HIGH] CWE-190 expat: Integer overflow in doProlog in xmlparse.c
expat: Integer overflow in doProlog in xmlparse.c
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
expat (libexpat) is susceptible to a software flaw that causes process interruption. When processing a large number of prefixed XML attributes on a single tag can libexpat can terminate unexpectedly due to integer overflow. The highest threat from this vulnerability is to availability, confidentiality and integrity.
Package: expat (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox (Red Hat Enterprise Linux 6) - Out of support scope
Package: thunderbird (Red Hat Enterprise Linux 6) - Out of support scope
Package: xulrunner (Red Hat Enterprise Linux 6) - Out of support scope
Package: firefox (Red Hat Enterprise
Microsoft
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3 an integer overflow exists for m_groupSize.
vendor_msrc·2022-01-11·CVSS 7.8
CVE-2021-46143 [HIGH] CWE-190 In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3 an integer overflow exists for m_groupSize.
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3 an integer overflow exists for m_groupSize.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Mariner: Mariner
mitre: mitre
Customer Action Required: Yes
Remediat
Debian
CVE-2021-46143: expat - In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overf...
vendor_debian·2021·CVSS 8.1
CVE-2021-46143 [HIGH] CVE-2021-46143: expat - In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overf...
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
Scope: local
bookworm: resolved (fixed in 2.4.3-1)
bullseye: resolved (fixed in 2.2.10-2+deb11u1)
forky: resolved (fixed in 2.4.3-1)
sid: resolved (fixed in 2.4.3-1)
trixie: resolved (fixed in 2.4.3-1)
No detection rules found.
No public exploits indexed.
Bugzilla
Recent expat CVEs
bugzilla·2022-02-10·CVSS 8.8
[HIGH] Recent expat CVEs
Recent expat CVEs
Lately some expat CVEs popped up [1], the expat is sandboxed in the version 96+
but the ESR seems not to be covered. Could you please investigate if the vulnerabilities has any relevancy for the Firefox?
[1] https://nvd.nist.gov/vuln/search/results?form_type=Basic&results_type=overview&query=expat&search_type=all&isCpeNameSearch=false
Discussion:
[Tracking Requested - why for this release]: possible sec issues
---
Bobby, do you think RLBoxing expat on ESR was feasible?
(as a possible alternative to updating expat)
---
* CVE-2021-45960, CVE-2021-46143, CVE-2022-22822 to CVE-2022-22827: needs to be verified, but on first glance I don't think we allow enough data into the parser to hit these.
* CVE-2022-23852: doesn't affect us, only affects "configurations with a n
Bugzilla
CVE-2021-46143 expat: Integer overflow in doProlog in xmlparse.c
bugzilla·2022-01-24·CVSS 7.8
CVE-2021-46143 [HIGH] CVE-2021-46143 expat: Integer overflow in doProlog in xmlparse.c
CVE-2021-46143 expat: Integer overflow in doProlog in xmlparse.c
In doProlog in xmlparse.c in Expat (aka libexpat) before 2.4.3, an integer overflow exists for m_groupSize.
References:
https://github.com/libexpat/libexpat/issues/532
https://github.com/libexpat/libexpat/pull/538
http://www.openwall.com/lists/oss-security/2022/01/17/3
Discussion:
Created expat tracking bugs for this issue:
Affects: fedora-all [bug 2044456]
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2022:0951 https://access.redhat.com/errata/RHSA-2022:0951
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 7
Via RHSA-2022:1069 https://access.redhat.com/errata/RHSA-2022:1069
---
This bug is now closed. Further updates for i
http://www.openwall.com/lists/oss-security/2022/01/17/3https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfhttps://github.com/libexpat/libexpat/issues/532https://github.com/libexpat/libexpat/pull/538https://security.gentoo.org/glsa/202209-24https://security.netapp.com/advisory/ntap-20220121-0006/https://www.debian.org/security/2022/dsa-5073https://www.tenable.com/security/tns-2022-05http://www.openwall.com/lists/oss-security/2022/01/17/3https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdfhttps://github.com/libexpat/libexpat/issues/532https://github.com/libexpat/libexpat/pull/538https://security.gentoo.org/glsa/202209-24https://security.netapp.com/advisory/ntap-20220121-0006/https://www.debian.org/security/2022/dsa-5073https://www.tenable.com/security/tns-2022-05
2022-01-06
Published