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CVE-2021-40438

Apache HTTP Server-Side Request Forgery (SSRF)

9.0 CRITICALActively exploited (CISA KEV)Used in ransomwareEPSS 100.0%
  1. Published16 Sept 2021
  2. Added to CISA KEV1 Dec 2021
  3. Remediation due15 Dec 2021
Actively exploited (CISA KEV)

A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

Added to KEV: 1 Dec 2021Federal remediation due: 15 Dec 2021Used in ransomware

Description

A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityHigh
Privileges requiredNone
User interactionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected products

Apache HTTP Server≤ 2.4.48
Netapp Cloud Backupall versions
Netapp Clustered Data Ontapall versions
Netapp Storagegridall versions
Oracle Enterprise Manager Ops Center12.4.0.0
Oracle HTTP Server12.2.1.3.0 · 12.2.1.4.0
Oracle Instantis Enterprisetrack17.1 · 17.2 · 17.3
Oracle Secure Global Desktop5.6
Oracle Zfs Storage Appliance Kit8.8
Redhat Jboss Core Services1.0
Redhat Software Collections1.0
Siemens Ruggedcom Nmsall versions
Siemens Sinec Nms< 1.0.3
Siemens Sinema Remote Connect Server< 3.1 · 3.2
Siemens Sinema Server14.0
Tenable Tenable.sc≤ 5.19.1
Broadcom Brocade Fabric Operating System Firmwareall versions
Debian Linux10.0 · 11.0 · 9.0
F5 F5os≥ 1.1.0 ≤ 1.1.4 · ≥ 1.2.0 ≤ 1.2.1
Fedoraproject Fedora34 · 35
Redhat Enterprise Linux Eus8.1 · 8.2 · 8.4 · 8.6
Redhat Enterprise Linux For Arm 648.0
Redhat Enterprise Linux For Arm 64 Eus8.6 · 8.8
Redhat Enterprise Linux For Ibm Z Systems7.0_s390x · 8.0

Remediation

Fixed in
Siemens Sinec Nms≥ 1.0.3
Siemens Sinema Remote Connect Server≥ 3.1

References

and 10 more references

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Frequently asked

Is CVE-2021-40438 being actively exploited?

Yes. CVE-2021-40438 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 1 Dec 2021. It has been used in ransomware campaigns.

How severe is CVE-2021-40438?

CVE-2021-40438 has a CVSS 3.1 base score of 9.0, rated critical. EPSS estimates a 100.0% probability of exploitation.

Which products are affected by CVE-2021-40438?

Affected products include Apache HTTP Server, Netapp Cloud Backup, Netapp Clustered Data Ontap, Netapp Storagegrid, Oracle Enterprise Manager Ops Center, and 19 more.

How do I fix CVE-2021-40438?

Upgrade affected software to a fixed version, for example Siemens Sinec Nms 1.0.3, Siemens Sinema Remote Connect Server 3.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-40438 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.