CVE-2021-26691— Apache HTTP Server mod_session response handling heap overflow
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I. Basic Information for CVE-2021-26691
Vulnerability Information
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Vulnerability Title
Apache HTTP Server mod_session response handling heap overflow
Source: NVD (National Vulnerability Database)
Vulnerability Description
In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
堆缓冲区溢出
Source: NVD (National Vulnerability Database)
Vulnerability Title
Apache HTTP Server 缓冲区错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Apache HTTP Server是美国阿帕奇（Apache）基金会的一款开源网页服务器。该服务器具有快速、可靠且可通过简单的API进行扩充的特点。 Apache HTTP Server 2.4.0 to 2.4.46存在缓冲区错误漏洞，该漏洞允许远程攻击者可利用该漏洞执行拒绝服务(DoS)攻击。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.46 | - |
II. Public POCs for CVE-2021-26691
| # | POC Description | Source Link | Shenlong Link |
|---|---|---|---|
| 1 | None | https://github.com/dja2TaqkGEEfA45/CVE-2021-26691 | POC Details |
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No public POC found.
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- https://www.oracle.com/security-alerts/cpujan2022.htmlx_refsource_MISC
- https://www.oracle.com/security-alerts/cpuoct2021.htmlx_refsource_MISC
- http://httpd.apache.org/security/vulnerabilities_24.htmlx_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210702-0001/x_refsource_CONFIRM
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/vendor-advisoryx_refsource_FEDORA
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2021-26691
Same Patch Batch · Apache Software Foundation · 2021-06-10 · 7 CVEs total
| CVE-2021-30641 | Unexpected URL matching with 'MergeSlashes OFF' | |
| CVE-2021-26690 | mod_session NULL pointer dereference | |
| CVE-2020-13950 | mod_proxy_http NULL pointer dereference | |
| CVE-2020-35452 | mod_auth_digest possible stack overflow by one nul byte | |
| CVE-2020-13938 | Improper Handling of Insufficient Privileges | |
| CVE-2019-17567 | mod_proxy_wstunnel tunneling of non Upgraded connections |
IV. Related Vulnerabilities
Same product: Apache HTTP Server
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Apache HTTP Server: http2: double free and possible RCE on e - CVE-2026-33006
Apache HTTP Server: mod_auth_digest timing attack
Same vendor: Apache Software Foundation
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Apache CloudStack: Domain/account resources limits not honor - CVE-2025-66467
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Same weakness: CWE-122
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