Squid vulnerabilities

CVE-2025-62168 [HIGH] CVE-2025-62168: Squid is a caching proxy for the Web Squid is a caching proxy for the Web. In Squid versions prior to 7.2, a failure to redact HTTP authentication credentials in error handling allows information disclosure. The vulnerability allows a script to bypass browser security protections and learn the credentials a trusted client uses to authenticate. This potentially allows a remote client to identify security tokens or credentials used internally by a web applicat

CVE-2021-31806 [MEDIUM] CVE-2021-31806: An issue was discovered in Squid before 4 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-2004-0541 [CRITICAL] CVE-2004-0541: Buffer overflow in the ntlm_check_auth (NTLM authentication) function for Squid Web Proxy Cache 2 Buffer overflow in the ntlm_check_auth (NTLM authentication) function for Squid Web Proxy Cache 2.5.x and 3.x, when compiled with NTLM handlers enabled, allows remote attackers to execute arbitrary code via a long password ("pass" variable).

CVE-2025-54574 [CRITICAL] CVE-2025-54574: Squid is a caching proxy for the Web Squid is a caching proxy for the Web. In versions 6.3 and below, Squid is vulnerable to a heap buffer overflow and possible remote code execution attack when processing URN due to incorrect buffer management. This has been fixed in version 6.4. To work around this issue, disable URN access permissions.

CVE-2020-11945 [CRITICAL] CVE-2020-11945: An issue was discovered in Squid before 5 An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).

CVE-2023-46847 [HIGH] CVE-2023-46847: Squid is vulnerable to a Denial of Service, where a remote attacker can perform buffer overflow attack by writing up to 2 MB of arbitrary data to heap Squid is vulnerable to a Denial of Service, where a remote attacker can perform buffer overflow attack by writing up to 2 MB of arbitrary data to heap memory when Squid is configured to accept HTTP Digest Authentication.

CVE-2023-49285 [HIGH] squid vulnerabilities squid vulnerabilities Joshua Rogers discovered that Squid incorrectly handled HTTP message processing. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2023-49285) Joshua Rogers discovered that Squid incorrectly handled Helper process management. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2023-49286) Joshua Rogers disco

CVE-2024-25617 [HIGH] CVE-2024-25617: Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to a Collapse of Data into Unsafe Value bug ,Squid may be vulnerable to a Denial of Service attack against HTTP header parsing. This problem allows a remote client or a remote server to perform Denial of Service when sending oversized headers in HTTP messages. In versions of Squid

CVE-2020-8450 [HIGH] CVE-2020-8450: An issue was discovered in Squid before 4 An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can cause a buffer overflow in a Squid instance acting as a reverse proxy.

CVE-2019-12527 [HIGH] CVE-2019-12527: An issue was discovered in Squid 4 An issue was discovered in Squid 4.0.23 through 4.7. When checking Basic Authentication with HttpHeader::getAuth, Squid uses a global buffer to store the decoded data. Squid does not check that the decoded length isn't greater than the buffer, leading to a heap-based buffer overflow with user controlled data.

CVE-2009-0478 [MEDIUM] CWE-20 CVE-2009-0478: Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a Squid 2.7 to 2.7.STABLE5, 3.0 to 3.0.STABLE12, and 3.1 to 3.1.0.4 allows remote attackers to cause a denial of service via an HTTP request with an invalid version number, which triggers a reachable assertion in (1) HttpMsg.c and (2) HttpStatusLine.c.

CVE-2021-31807 [MEDIUM] CVE-2021-31807: An issue was discovered in Squid before 4 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-2019-12525 [CRITICAL] CVE-2019-12525: An issue was discovered in Squid 3 An issue was discovered in Squid 3.3.9 through 3.5.28 and 4.x through 4.7. When Squid is configured to use Digest authentication, it parses the header Proxy-Authorization. It searches for certain tokens such as domain, uri, and qop. Squid checks if this token's value starts with a quote and ends with one. If so, it performs a memcpy of its length minus 2. Squid never checks whether the value is just a single quote (whic

CVE-2023-50269 [HIGH] CVE-2023-50269: Squid is a caching proxy for the Web Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. Th

CVE-2024-25111 [HIGH] CVE-2024-25111: Squid is a web proxy cache Squid is a web proxy cache. Starting in version 3.5.27 and prior to version 6.8, Squid may be vulnerable to a Denial of Service attack against HTTP Chunked decoder due to an uncontrolled recursion bug. This problem allows a remote attacker to cause Denial of Service when sending a crafted, chunked, encoded HTTP Message. This bug is fixed in Squid version 6.8. In addition, patches addressing this problem for the stable releases can

CVE-2002-0163 [HIGH] CVE-2002-0163: Heap-based buffer overflow in Squid before 2.4 STABLE4, and Squid 2.5 and 2.6 until March 12, 2002 d Heap-based buffer overflow in Squid before 2.4 STABLE4, and Squid 2.5 and 2.6 until March 12, 2002 distributions, allows remote attackers to cause a denial of service, and possibly execute arbitrary code, via compressed DNS responses.

CVE-2019-12526 [CRITICAL] CVE-2019-12526: An issue was discovered in Squid before 4 An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in the heap.

CVE-2016-4554 [HIGH] CVE-2016-4554: mime_header mime_header.cc in Squid before 3.5.18 allows remote attackers to bypass intended same-origin restrictions and possibly conduct cache-poisoning attacks via a crafted HTTP Host header, aka a "header smuggling" issue.

CVE-2024-45802 [HIGH] CVE-2024-45802: Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more Squid is an open source caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Due to Input Validation, Premature Release of Resource During Expected Lifetime, and Missing Release of Resource after Effective Lifetime bugs, Squid is vulnerable to Denial of Service attacks by a trusted server against all clients using the proxy. This bug is fixed in the default bu

CVE-2019-18679 [HIGH] CVE-2019-18679: An issue was discovered in Squid 2 An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR protections and may aid attackers isolating memory areas to target for remote code execution attacks.