Linux/Unix 主機上安裝了一個或多個受到弱點影響的套件，且供應商未提供可用的修補程式。

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於輸入驗證錯誤，此弱點容易遭受拒絕服務攻擊 (針對使用 Proxy 的所有用戶端)。用戶端會傳送 HTTP 範圍請求以觸發此要求。(CVE-2021-31808)

請注意，Nessus 的判定取決於廠商所報告的套件是否存在。

遠端 Rocky Linux 8 主機已安裝受到多個弱點影響的套件如 RLSA-2021:4292 公告中所提及。

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於存在緩衝區管理錯誤，可觸發拒絕服務攻擊。解析具有 urn: 配置的要求時剖析器會洩漏少量記憶體。不過，有個不明攻擊方法可輕易觸發大量記憶體耗用。(CVE-2021-28651)

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於不正確的剖析器驗證所致，此弱點允許對 Cache Manager API 發動拒絕服務攻擊。這會允許受信任的用戶端觸發記憶體洩漏。過一陣子後就會透過不明的簡短查詢字串導致拒絕服務。此攻擊僅限於具有 Cache Manager API 存取特權的用戶端。(CVE-2021-28652)

  在 4.15 之前的 Squid 4.x 和 5.0.6 之前的 5.x 中發現一個問題。若遠端伺服器透過 HTTP 或 HTTPS 傳送特定回應標頭，會發生拒絕服務的情形。此標頭可能會在安全的網路流量中合理地發生。(CVE-2021-28662)

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於記憶體管理的錯誤，此弱點容易透過 HTTP 範圍請求處理受到拒絕服務攻擊的影響 (針對使用 Proxy 的所有用戶端)。 (CVE-2021-31806)

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於存在整數溢位問題，在傳送對 HTTP Range 要求的回應時，遠端伺服器會拒絕服務。預期存在於 HTTP 流量中且沒有惡意的標頭可觸發此問題。
    (CVE-2021-31807)

  在 4.15 版之前和 5.0.6 之前 5.x 版的 Squid 中，發現一個問題。由於輸入驗證錯誤，此弱點容易遭受拒絕服務攻擊 (針對使用 Proxy 的所有用戶端)。用戶端會傳送 HTTP 範圍請求以觸發此要求。(CVE-2021-31808)

  - 4.15 之前的 Squid 和 5.0.6 之前的 5.x 允許遠端伺服器透過 HTTP 回應導致拒絕服務 (影響所有用戶端的可用性)。此問題的觸發程序為標頭，伺服器可能會判定其應存在於 HTTP 流量中，且沒有惡意。(CVE-2021-33620)

請注意，Nessus 並未測試這些問題，而是僅依據應用程式自我報告的版本號碼作出判斷。

遠端主機受到 GLSA-202105-14 中所述的弱點影響 (Squid：多個弱點)

    在 Squid 中發現多個弱點。如需詳細資訊，請檢閱下方提及的 CVE 識別碼。
  影響：

    遠端攻擊者可傳送特製的要求，進而可能導致拒絕服務或資訊洩漏。
  因應措施：

    目前尚無已知的因應措施。

遠端 CentOS Linux 8 主機上安裝的套件受到 CESA-2021: 4292 公告中提及的多個弱點影響。

  - squid：URN 處理過程中的拒絕服務 (CVE-2021-28651)

  - squid：Cache Manager 中的拒絕服務 (CVE-2021-28652)

  - squid：HTTP 回應處理過程中的拒絕服務 (CVE-2021-28662、CVE-2021-33620)

  - squid：HTTP Range 標頭中的不當輸入驗證 (CVE-2021-31806)

  - squid：HTTP Range 標頭中的不正確記憶體管理 (CVE-2021-31807)

  - squid：HTTP Range 標頭中的整數溢位 (CVE-2021-31808)

請注意，Nessus 並未測試此問題，而是僅依據應用程式自我報告的版本號碼。

The version of squid installed on the remote host is prior to 4.15-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2SQUID4-2023-004 advisory.

    Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of     an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code     execution as nobody. (CVE-2021-28116)

    An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it     allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount     of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of     memory consumption. (CVE-2021-28651)

    An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to incorrect parser validation, it     allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger     memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This     attack is limited to clients with Cache Manager API access privilege. (CVE-2021-28652)

    An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain     response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in     benign network traffic. (CVE-2021-28662)

    An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is     vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request     processing. (CVE-2021-31806)

    An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. An integer overflow problem allows a     remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue     trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.
    (CVE-2021-31807)

    An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to an input-validation bug, it is     vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP     Range request to trigger this. (CVE-2021-31808)

    Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting     availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to     exist in HTTP traffic without any malicious intent by the server. (CVE-2021-33620)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4981-1 advisory.

    Joshua Rogers discovered that Squid incorrectly handled requests with the urn: scheme. A remote attacker     could possibly use this issue to cause Squid to consume resources, leading to a denial of service.
    (CVE-2021-28651)

    Joshua Rogers discovered that Squid incorrectly handled requests to the Cache Manager API. A remote     attacker with access privileges could possibly use this issue to cause Squid to consume resources, leading     to a denial of service. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04.
    (CVE-2021-28652)

    Joshua Rogers discovered that Squid incorrectly handled certain response headers. A remote attacker could     possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue was only     affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662)

    Joshua Rogers discovered that Squid incorrectly handled range request processing. A remote attacker could     possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-31806,     CVE-2021-31807, CVE-2021-31808)

    Joshua Rogers discovered that Squid incorrectly handled certain HTTP responses. A remote attacker could     possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2021-33620)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Several vulnerabilities were discovered in Squid, a proxy caching server. 

CVE-2021-28651

Due to a buffer-management bug, it allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of memory consumption.

CVE-2021-28652

Due to incorrect parser validation, it allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This attack is limited to clients with Cache Manager API access privilege.

CVE-2021-31806

Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing.

CVE-2021-31807

An integer overflow problem allows a remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.

CVE-2021-31808

Due to an input-validation bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP Range request to trigger this.

CVE-2021-33620

Remote servers to cause a denial of service (affecting availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent by the server.

For Debian 9 stretch, these problems have been fixed in version 3.5.23-5+deb9u7.

We recommend that you upgrade your squid3 packages.

For the detailed security status of squid3 please refer to its security tracker page at:
https://security-tracker.debian.org/tracker/squid3

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the squid packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in Squid before 4.12 and 5.x     before 5.0.3. Due to use of a potentially dangerous     function, Squid and the default certificate validation     helper are vulnerable to a Denial of Service when     opening a TLS connection to an attacker-controlled     server for HTTPS. This occurs because unrecognized     error values are mapped to NULL, but later code expects     that each error value is mapped to a valid error     string.(CVE-2020-14058)

  - An issue was discovered in Squid through 4.13 and 5.x     through 5.0.4. Due to improper input validation, it     allows a trusted client to perform HTTP Request     Smuggling and access services otherwise forbidden by     the security controls. This occurs for certain     uri_whitespace configuration settings.(CVE-2020-25097)

  - An issue was discovered in Squid before 4.15 and 5.x     before 5.0.6. Due to an input-validation bug, it is     vulnerable to a Denial of Service attack (against all     clients using the proxy). A client sends an HTTP Range     request to trigger this.(CVE-2021-31808)

  - An issue was discovered in Squid before 4.15 and 5.x     before 5.0.6. Due to a buffer-management bug, it allows     a denial of service. When resolving a request with the     urn: scheme, the parser leaks a small amount of memory.
    However, there is an unspecified attack methodology     that can easily trigger a large amount of memory     consumption.(CVE-2021-28651)

  - An issue was discovered in Squid before 4.15 and 5.x     before 5.0.6. Due to a memory-management bug, it is     vulnerable to a Denial of Service attack (against all     clients using the proxy) via HTTP Range request     processing.(CVE-2021-31806)

  - Squid before 4.15 and 5.x before 5.0.6 allows remote     servers to cause a denial of service (affecting     availability to all clients) via an HTTP response. The     issue trigger is a header that can be expected to exist     in HTTP traffic without any malicious intent by the     server.(CVE-2021-33620)

  - An issue was discovered in Squid before 4.15 and 5.x     before 5.0.6. An integer overflow problem allows a     remote server to achieve Denial of Service when     delivering responses to HTTP Range requests. The issue     trigger is a header that can be expected to exist in     HTTP traffic without any malicious     intent.(CVE-2021-31807)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	名前	製品	ファミリー	公開日	更新日	深刻度
252911	Linux Distros 未修補的弱點：CVE-2021-31808	Nessus	Misc.	2025/8/20	2025/8/20	medium
185083	Rocky Linux 8squid:4 (RLSA-2021:4292)	Nessus	Rocky Linux Local Security Checks	2023/11/7	2023/11/7	high
150021	GLSA-202105-14 ：Squid：多個弱點	Nessus	Gentoo Local Security Checks	2021/5/27	2024/1/12	high
155039	CentOS 8：squid：4 (CESA-2021: 4292)	Nessus	CentOS Local Security Checks	2021/11/11	2023/11/24	high
181987	Amazon Linux 2 : squid (ALASSQUID4-2023-004)	Nessus	Amazon Linux Local Security Checks	2023/9/27	2024/12/11	medium
150232	Ubuntu 18.04 LTS / 20.04 LTS : Squid vulnerabilities (USN-4981-1)	Nessus	Ubuntu Local Security Checks	2021/6/3	2024/8/27	high
150796	Debian DLA-2685-1 : squid3 security update	Nessus	Debian Local Security Checks	2021/6/15	2023/12/21	high
153296	EulerOS 2.0 SP2 : squid (EulerOS-SA-2021-2433)	Nessus	Huawei Local Security Checks	2021/9/14	2023/11/30	high

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