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NVD / CVE Program· CNA apache

CVE-2016-8743: Apache HTTP Server, in all releases prior to 2.2.32 and 2.4.25, was liberal in the whitespace accepted from requests and sent in response…

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 13.2% (FIRST EPSS); higher than 96.4% of all records.
  • 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.
  • Fixed version: apache2 (Debian:12) 2.4.25-1; apache2 (Debian:7) 2.2.22-13+deb7u11, 2.2.22-13+deb7u8; apache2 (Debian:8) 2.4.10-10+deb8u8.

Low priority for now. Upgrade to apache2 (Debian:12) 2.4.25-1; apache2 (Debian:7) 2.2.22-13+deb7u11, 2.2.22-13+deb7u8; apache2 (Debian:8) 2.4.10-10+deb8u8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Apache HTTP Server, in all releases prior to 2.2.32 and 2.4.25, was liberal in the whitespace accepted from requests and sent in response lines and headers. Accepting these different behaviors represented a security concern when httpd participates in any chain of proxies or interacts with back-end application servers, either through mod_proxy or using conventional CGI mechanisms, and may result in request smuggling, response splitting and cache pollution.

Published
Jul 27, 2017
Updated
Jun 16, 2026
EPSS
13.2% · 96th percentile
CWE
—

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
4 / 30 · 13.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
apachehttp server
netappclustered data ontap
netapponcommand unified manager
debiandebian linux
redhatenterprise linux desktop
redhatenterprise linux eus
redhatenterprise linux server
redhatenterprise linux server aus
redhatenterprise linux server tus
redhatenterprise linux workstation
redhatjboss core services
redhatenterprise linux

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When you'll hear from us

  • when a new CVE affecting this product is published
  • when a record in your stack enters KEV or is weaponized

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Is Apache HTTP Server on your server exposed to the internet?Run a port scan

Your free account also gets you

  • CVE alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every Monday

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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 2.2.31, 2.4.1 to 2.4.23affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache http server2.2.0 and later · up to 2.2.31 inclusive
  • apache http server2.4.1 and later · up to 2.4.23 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12apache2before 2.4.25-12.4.25-1
Debian:7apache2before 2.2.22-13+deb7u112.2.22-13+deb7u11
Debian:7apache2before 2.2.22-13+deb7u82.2.22-13+deb7u8
Debian:8apache2before 2.4.10-10+deb8u82.4.10-10+deb8u8
Red Hat:enterprise_linux:6::clienthttpdbefore 0:2.2.15-60.el6_9.40:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:6::clienthttpd-debuginfobefore 0:2.2.15-60.el6_9.40:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:6::clienthttpd-develbefore 0:2.2.15-60.el6_9.40:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:6::clienthttpd-manualbefore 0:2.2.15-60.el6_9.40:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:6::clienthttpd-toolsbefore 0:2.2.15-60.el6_9.40:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:6::clientmod_sslbefore 1:2.2.15-60.el6_9.41:2.2.15-60.el6_9.4
Red Hat:enterprise_linux:7::clienthttpdbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clienthttpd-debuginfobefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clienthttpd-develbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clienthttpd-manualbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clienthttpd-toolsbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clientmod_ldapbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clientmod_proxy_htmlbefore 1:2.4.6-45.el7_3.41:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clientmod_sessionbefore 0:2.4.6-45.el7_3.40:2.4.6-45.el7_3.4
Red Hat:enterprise_linux:7::clientmod_sslbefore 1:2.4.6-45.el7_3.41:2.4.6-45.el7_3.4
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpdbefore 0:2.4.23-120.jbcs.el60:2.4.23-120.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-debuginfobefore 0:2.4.23-120.jbcs.el60:2.4.23-120.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-develbefore 0:2.4.23-120.jbcs.el60:2.4.23-120.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-libsbefore 0:2.4.23-120.jbcs.el60:2.4.23-120.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-manualbefore 0:2.4.23-120.jbcs.el60:2.4.23-120.jbcs.el6

+56

Same product

apache: all records

Other 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)KEV
    99Now
  • CVE-2021-41773Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49KEV
    99Now
  • CVE-2024-38475Apache HTTP Server weakness in mod_rewrite when first segment of substitution matches filesystem path.KEV
    96Now

Published before and after this one in the same product

  • ← EarlierCVE-2016-0736Jul 27, 2017 · In Apache HTTP Server versions 2.4.0 to 2.4.23, mod_session_crypto was encrypting its data/cookie using the configured ciphers with…
    45Plan
  • ← EarlierCVE-2016-2161Jul 27, 2017 · In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance…
    36Monitor
  • Later →CVE-2017-9798Sep 18, 2017 · Apache httpd allows remote attackers to read secret data from process memory if the Limit directive can be set in a user's .htaccess file…
    60This 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 / packageFixed versionSource
debian:apache22.4.25-1 · Debian:12Package registry (OSV)
red hat:httpd0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:httpd-debuginfo0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:httpd-devel0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:httpd-manual0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:httpd-tools0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:httpd24-httpd0:2.4.25-9.el6 · Red Hat:rhel_software_collections:2::el6Package registry (OSV)
red hat:httpd24-httpd-debuginfo0:2.4.25-9.el6 · Red Hat:rhel_software_collections:2::el6Package registry (OSV)
red hat:httpd24-httpd-devel0:2.4.25-9.el6 · Red Hat:rhel_software_collections:2::el6Package registry (OSV)
red hat:mod_ldap0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:mod_proxy_html1:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:mod_session0:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:mod_ssl1:2.4.6-45.el7_3.4 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
suse:apache22.2.12-69.1 · SUSE:Linux Enterprise Software Development Kit 11 SP4Package 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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records