CVE-2020-35452
HighApache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in mod_auth_digest.
Published Jul 12, 2021 · Updated Sep 8, 2026 · Also known as ALPINE-CVE-2020-35452, BIT-apache-2020-35452, DEBIAN-CVE-2020-35452, DSA-4937-1, SUSE-SU-2021:14749-1, SUSE-SU-2021:2006-1, TR-21-0565, UBUNTU-CVE-2020-35452, USN-4994-2
Key Facts
Patch immediately- CVE-2020-35452 is a high-severity vulnerability (CVSS 7.3 v3.1) affecting HTTP Server (Apache), Enterprise Manager Ops Center (Oracle), Instantis Enterprisetrack (Oracle) and 22 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 55% probability of exploitation in the next 30 days.
- Fixed versions are available, including apache 2.4.47, apache 2.4.47-1, HTTP Server <=2.4.46.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
7.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS (30-day exploit likelihood)
55%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2020-35452 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team could create one, though some particular compiler and/or compilation option might make it possible, with limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow
Affected Products
351 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | >= 2.4.46 | 2.4.46 |
| Enterprise Manager Ops CenterOracle | 12.4.0.0 | n/a |
| Instantis EnterprisetrackOracle | 17.1, 17.2, 17.3 | n/a |
| Zfs Storage Appliance KitOracle | 8.8 | n/a |
| Debian LinuxDebian | 10.0, 9.0 | n/a |
Patched Releases
apache
2.4.47, 2.4.47-1
HTTP Server
<=2.4.46
apache2
2.2.34-70.35.1, 2.4.18-2ubuntu3.17+esm1, 2.4.23-29.74.1, 2.4.25-3+deb9u10, 2.4.29-1ubuntu4.16, 2.4.33-3.50.1, 2.4.38-3+deb10u5, 2.4.41-4ubuntu3.3, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1, 2.4.46-6, 2.4.48-r0, 2.4.7-1ubuntu4.22+esm1
apache2-devel
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.33-3.50.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-doc
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.33-3.50.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-event
2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-example-pages
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-prefork
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.33-3.50.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-utils
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.33-3.50.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
apache2-worker
2.2.34-70.35.1, 2.4.23-29.74.1, 2.4.33-3.50.1, 2.4.43-3.22.1, 2.4.43-lp152.2.15.1
httpd
2.4.37-47.0.1.module+el8.6.0+20649+083145da.1, 2.4.37-47.module_el8.6.0+2872+fe0ff7aa.1.alma, 2.4.37-47.module+el8.6.0+823+f143cee1.1, 2.4.37-47.module+el8.6.0+985+b8ff6398.2, 2.4.46-10, 2.4.46-5, 2.4.48-1.ph1, 2.4.48-1.ph2, 2.4.48-1.ph3, 2.4.48-2.amzn2
httpd-devel
2.4.37-47.0.1.module+el8.6.0+20649+083145da.1, 2.4.48-2.amzn2
httpd-filesystem
2.4.37-47.0.1.module+el8.6.0+20649+083145da.1, 2.4.48-2.amzn2
httpd-manual
2.4.37-47.0.1.module+el8.6.0+20649+083145da.1, 2.4.48-2.amzn2
httpd-tools
2.4.37-47.0.1.module+el8.6.0+20649+083145da.1, 2.4.48-2.amzn2
httpd:2.4
8060020220321163517.d63f516d
httpd24
2.4.48-1.92.amzn1
httpd24-devel
2.4.48-1.92.amzn1
httpd24-manual
2.4.48-1.92.amzn1
httpd24-tools
2.4.48-1.92.amzn1
jbcs-httpd24-apr
0:1.6.3-107.el8jbcs, 0:1.6.3-107.jbcs.el7
jbcs-httpd24-apr-util
0:1.6.1-84.el8jbcs, 0:1.6.1-84.jbcs.el7
jbcs-httpd24-curl
0:7.78.0-2.el8jbcs, 0:7.78.0-2.jbcs.el7
jbcs-httpd24-httpd
0:2.4.37-78.el8jbcs, 0:2.4.37-78.jbcs.el7
jbcs-httpd24-mod_cluster-native
0:1.3.16-9.Final_redhat_2.el8jbcs, 0:1.3.16-9.Final_redhat_2.jbcs.el7
Timeline
Publicly disclosed
Jul 12, 2021
Last updated
Sep 8, 2026
Weakness Type
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
- CWE-787 Out-of-bounds Write
References
- advisoryhttp://httpd.apache.org/security/vulnerabilities_24.html
- advisoryRHSA-2021:4613
- advisoryRHSA-2021:4614
- advisoryRHSA-2022:1915
- advisoryhttps://bugzilla.suse.com/1145740
FAQ
Common Questions.
Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in mod_auth_digest.
Affected: HTTP Server (Apache) versions >= 2.4.46; Enterprise Manager Ops Center (Oracle) versions 12.4.0.0; Instantis Enterprisetrack (Oracle) versions 17.1, 17.2, 17.3, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including apache 2.4.47, apache 2.4.47-1, HTTP Server <=2.4.46.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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