// For flags

CVE-2025-53020

Apache HTTP Server: HTTP/2 DoS by Memory Increase

Severity Score

7.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Attend
*SSVC
Descriptions

Late Release of Memory after Effective Lifetime vulnerability in Apache HTTP Server. This issue affects Apache HTTP Server: from 2.4.17 up to 2.4.63. Users are recommended to upgrade to version 2.4.64, which fixes the issue.

It was discovered that the Apache HTTP Server incorrectly handled certain Content-Type response headers. A remote attacker could possibly use this issue to perform HTTP response splitting attacks. xiaojunjie discovered that the Apache HTTP Server mod_proxy module incorrectly handled certain requests. A remote attacker could possibly use this issue to send outbound proxy requests to an arbitrary URL.

*Credits: Gal Bar Nahum
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Attend
Exploitation
None
Automatable
Yes
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-06-24 CVE Reserved
  • 2025-07-10 CVE Published
  • 2025-07-15 CVE Updated
  • 2025-07-16 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-401: Missing Release of Memory after Effective Lifetime
CAPEC
References (1)
URL Tag Source
URL Date SRC
URL Date SRC
URL Date SRC
https://httpd.apache.org/security/vulnerabilities_24.html 2025-07-10
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Apache Software Foundation
Search vendor "Apache Software Foundation"
 Apache HTTP Server
Search vendor "Apache Software Foundation" for product "Apache HTTP Server"
 >= 2.4.17 <= 2.4.63
Search vendor "Apache Software Foundation" for product "Apache HTTP Server" and version " >= 2.4.17 <= 2.4.63"
en
Affected