In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initi
In Apache httpd before 2.2.34 and 2.4.x before 2.4.27, the value placeholder in [Proxy-]Authorization headers of type 'Digest' was not initialized or reset before or between successive key=value assignments by mod_auth_digest. Providing an initial key with no '=' assignment could reflect the stale value of uninitialized pool memory used by the prior request, leading to leakage of potentially confidential information, and a segfault in other cases resulting in denial of service.
- Published
- Jul 13, 2017
- Updated
- Jun 16, 2026
- EPSS
- 56.8% · 99th percentile
- CWE
- CWE-20
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Report tools
Action score
53
Plan
Add it to your regular patch cycle.
- CVSS
- 36 / 40 · 9.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 17 / 30 · 56.8%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| apache | http server | cpe:2.3:a:apache:http_server |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| apple | mac os x | cpe:2.3:o:apple:mac_os_x |
| netapp | oncommand unified manager | cpe:2.3:a:netapp:oncommand_unified_manager |
| netapp | storage automation store | cpe:2.3:a:netapp:storage_automation_store |
| redhat | enterprise linux desktop | cpe:2.3:o:redhat:enterprise_linux_desktop |
| redhat | enterprise linux server | cpe:2.3:o:redhat:enterprise_linux_server |
| redhat | enterprise linux server aus | cpe:2.3:o:redhat:enterprise_linux_server_aus |
| redhat | enterprise linux server eus | cpe:2.3:o:redhat:enterprise_linux_server_eus |
| redhat | enterprise linux server tus | cpe:2.3:o:redhat:enterprise_linux_server_tus |
| redhat | enterprise linux workstation | cpe:2.3:o:redhat:enterprise_linux_workstation |
| redhat | jboss core services | cpe:2.3:a:redhat:jboss_core_services |
and 4 more
Using http server? Add it to your stack and be the first to know about CVEs like this one. (Apache HTTP)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- apache http serverup to 2.2.33 inclusive
- apache http server2.4.0 and later · up to 2.4.26 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.
Apache Software Foundation Apache HTTP Server
- 2.2.0 to 2.2.33, 2.4.1 to 2.4.26affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | apache2 | before 2.4.27-1 | 2.4.27-1 |
| Debian:7 | apache2 | before 2.2.22-13+deb7u10 | 2.2.22-13+deb7u10 |
| Debian:8 | apache2 | before 2.4.10-10+deb8u10 | 2.4.10-10+deb8u10 |
| Debian:9 | apache2 | before 2.4.25-3+deb9u2 | 2.4.25-3+deb9u2 |
| Red Hat:enterprise_linux:6::client | httpd | before 0:2.2.15-60.el6_9.5 | 0:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:6::client | httpd-debuginfo | before 0:2.2.15-60.el6_9.5 | 0:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:6::client | httpd-devel | before 0:2.2.15-60.el6_9.5 | 0:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:6::client | httpd-manual | before 0:2.2.15-60.el6_9.5 | 0:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:6::client | httpd-tools | before 0:2.2.15-60.el6_9.5 | 0:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:6::client | mod_ssl | before 1:2.2.15-60.el6_9.5 | 1:2.2.15-60.el6_9.5 |
| Red Hat:enterprise_linux:7::client | httpd | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | httpd-debuginfo | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | httpd-devel | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | httpd-manual | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | httpd-tools | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | mod_ldap | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | mod_proxy_html | before 1:2.4.6-67.el7_4.2 | 1:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | mod_session | before 0:2.4.6-67.el7_4.2 | 0:2.4.6-67.el7_4.2 |
| Red Hat:enterprise_linux:7::client | mod_ssl | before 1:2.4.6-67.el7_4.2 | 1:2.4.6-67.el7_4.2 |
| Red Hat:jboss_core_services:1::el6 | jbcs-httpd24-httpd | before 0:2.4.23-122.jbcs.el6 | 0:2.4.23-122.jbcs.el6 |
| Red Hat:jboss_core_services:1::el6 | jbcs-httpd24-httpd-debuginfo | before 0:2.4.23-122.jbcs.el6 | 0:2.4.23-122.jbcs.el6 |
| Red Hat:jboss_core_services:1::el6 | jbcs-httpd24-httpd-devel | before 0:2.4.23-122.jbcs.el6 | 0:2.4.23-122.jbcs.el6 |
| Red Hat:jboss_core_services:1::el6 | jbcs-httpd24-httpd-libs | before 0:2.4.23-122.jbcs.el6 | 0:2.4.23-122.jbcs.el6 |
| Red Hat:jboss_core_services:1::el6 | jbcs-httpd24-httpd-manual | before 0:2.4.23-122.jbcs.el6 | 0:2.4.23-122.jbcs.el6 |
+96
Same product
apache: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-42013Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)KEV99Now
- CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV99Now
- CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV96Now
- CVE-2019-0211In Apache HTTP Server 2.4 releases 2.4.17 to 2.4.38, with MPM event, worker or prefork, code executing in less-privileged child processes orKEV81Now
- CVE-2021-44790Possible buffer overflow when parsing multipart content in mod_lua of Apache HTTP Server 2.4.51 and earlier68This week
- CVE-2010-0425modules/arch/win32/mod_isapi.c in mod_isapi in the Apache HTTP Server 2.0.37 through 2.0.63, 2.2.0 through 2.2.14, and 2.3.x before 2.3.7, w68This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:apache2 | 2.4.27-1 · Debian:12 | Package registry (OSV) |
| red hat:httpd | 0:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:httpd-debuginfo | 0:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:httpd-devel | 0:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:httpd-manual | 0:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:httpd-tools | 0:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:httpd24-httpd | 0:2.4.25-9.el6.1 · Red Hat:rhel_software_collections:2::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-debuginfo | 0:2.4.25-9.el6.1 · Red Hat:rhel_software_collections:2::el6 | Package registry (OSV) |
| red hat:httpd24-httpd-devel | 0:2.4.25-9.el6.1 · Red Hat:rhel_software_collections:2::el6 | Package registry (OSV) |
| red hat:mod_ldap | 0:2.4.6-67.el7_4.2 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:mod_proxy_html | 1:2.4.6-67.el7_4.2 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:mod_session | 0:2.4.6-67.el7_4.2 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:mod_ssl | 1:2.2.15-60.el6_9.5 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| suse:apache2 | 2.4.23-29.3.2 · SUSE:Linux Enterprise Server for Raspberry Pi 12 SP2 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- www.debian.org/security/2017/dsa-3913
- www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
- www.securityfocus.com/bid/99569
- www.securitytracker.com/id/1038906
- access.redhat.com/errata/RHSA-2017:2478
- access.redhat.com/errata/RHSA-2017:2479
- access.redhat.com/errata/RHSA-2017:2483
- access.redhat.com/errata/RHSA-2017:2708
- access.redhat.com/errata/RHSA-2017:2709
- access.redhat.com/errata/RHSA-2017:2710
- access.redhat.com/errata/RHSA-2017:3113
- access.redhat.com/errata/RHSA-2017:3114
- access.redhat.com/errata/RHSA-2017:3193
- access.redhat.com/errata/RHSA-2017:3194
- access.redhat.com/errata/RHSA-2017:3195
- access.redhat.com/errata/RHSA-2017:3239
- access.redhat.com/errata/RHSA-2017:3240
- httpd.apache.org/security/vulnerabilities_22.html
- httpd.apache.org/security/vulnerabilities_24.html
- lists.apache.org/thread.html/0dd69204a6bd643cc4e9ccd008f07a9375525d977c6ebeb07a881afb%40%3Cannounce.httpd.apache.org%3E
Vendor advisories and official records. Exploit/PoC links are deliberately left out.