Vulnerabilities (CVE)

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Total 88 CVE
CVE Vendors Products Updated CVSS v2 CVSS v3
CVE-2020-25097 4 Debian, Fedoraproject, Netapp and 1 more 4 Debian Linux, Fedora, Cloud Manager and 1 more 2022-04-05 5.0 MEDIUM 8.6 HIGH
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-2021-41611 2 Fedoraproject, Squid-cache 2 Fedora, Squid 2022-03-31 5.0 MEDIUM 7.5 HIGH
An issue was discovered in Squid 5.0.6 through 5.1.x before 5.2. When validating an origin server or peer certificate, Squid may incorrectly classify certain certificates as trusted. This problem allows a remote server to obtain security trust well improperly. This indication of trust may be passed along to clients, allowing access to unsafe or hijacked services.
CVE-2019-12854 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2022-01-01 5.0 MEDIUM 7.5 HIGH
Due to incorrect string termination, Squid cachemgr.cgi 4.0 through 4.7 may access unallocated memory. On systems with memory access protections, this can cause the CGI process to terminate unexpectedly, resulting in a denial of service for all clients using it.
CVE-2021-31806 4 Debian, Fedoraproject, Netapp and 1 more 4 Debian Linux, Fedora, Cloud Manager and 1 more 2021-09-14 4.0 MEDIUM 6.5 MEDIUM
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-2021-28651 4 Debian, Fedoraproject, Netapp and 1 more 4 Debian Linux, Fedora, Cloud Manager and 1 more 2021-09-14 5.0 MEDIUM 7.5 HIGH
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-2021-31807 3 Fedoraproject, Netapp, Squid-cache 3 Fedora, Cloud Manager, Squid 2021-09-14 4.0 MEDIUM 6.5 MEDIUM
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-2020-24606 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-07-21 7.1 HIGH 7.5 HIGH
Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply() livelocking in peer_digest.cc mishandles EOF.
CVE-2020-8517 3 Canonical, Opensuse, Squid-cache 3 Ubuntu Linux, Leap, Squid 2021-07-21 5.0 MEDIUM 7.5 HIGH
An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with memory access protections, this can result in the helper process being terminated unexpectedly. This leads to the Squid process also terminating and a denial of service for all clients using the proxy.
CVE-2019-12521 4 Canonical, Debian, Opensuse and 1 more 4 Ubuntu Linux, Debian Linux, Leap and 1 more 2021-07-21 4.3 MEDIUM 5.9 MEDIUM
An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.
CVE-2020-8450 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-07-21 7.5 HIGH 7.3 HIGH
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-2020-14059 1 Squid-cache 1 Squid 2021-03-30 4.0 MEDIUM 6.5 MEDIUM
An issue was discovered in Squid 5.x before 5.0.3. Due to an Incorrect Synchronization, a Denial of Service can occur when processing objects in an SMP cache because of an Ipc::Mem::PageStack::pop ABA problem during access to the memory page/slot management list.
CVE-2020-15810 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-03-17 3.5 LOW 6.5 MEDIUM
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Smuggling attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the proxy cache and any downstream caches with content from an arbitrary source. When configured for relaxed header parsing (the default), Squid relays headers containing whitespace characters to upstream servers. When this occurs as a prefix to a Content-Length header, the frame length specified will be ignored by Squid (allowing for a conflicting length to be used from another Content-Length header) but relayed upstream.
CVE-2020-11945 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-03-17 7.5 HIGH 9.8 CRITICAL
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-2020-15049 2 Fedoraproject, Squid-cache 2 Fedora, Squid 2021-03-12 6.5 MEDIUM 8.8 HIGH
An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing "+\ "-" or an uncommon shell whitespace character prefix to the length field-value.
CVE-2019-12522 1 Squid-cache 1 Squid 2021-03-10 4.4 MEDIUM 4.5 MEDIUM
An issue was discovered in Squid through 4.7. When Squid is run as root, it spawns its child processes as a lesser user, by default the user nobody. This is done via the leave_suid call. leave_suid leaves the Saved UID as 0. This makes it trivial for an attacker who has compromised the child process to escalate their privileges back to root.
CVE-2020-15811 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-03-04 4.0 MEDIUM 6.5 MEDIUM
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Splitting attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the browser cache and any downstream caches with content from an arbitrary source. Squid uses a string search instead of parsing the Transfer-Encoding header to find chunked encoding. This allows an attacker to hide a second request inside Transfer-Encoding: it is interpreted by Squid as chunked and split out into a second request delivered upstream. Squid will then deliver two distinct responses to the client, corrupting any downstream caches.
CVE-2020-8449 5 Canonical, Debian, Fedoraproject and 2 more 5 Ubuntu Linux, Debian Linux, Fedora and 2 more 2021-03-04 5.0 MEDIUM 7.5 HIGH
An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.
CVE-2019-12519 4 Canonical, Debian, Opensuse and 1 more 4 Ubuntu Linux, Debian Linux, Leap and 1 more 2021-02-11 7.5 HIGH 9.8 CRITICAL
An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a new member to the stack. When adding a new member, there is no check to ensure that the stack won't overflow.
CVE-2019-12520 3 Canonical, Debian, Squid-cache 3 Ubuntu Linux, Debian Linux, Squid 2021-02-11 5.0 MEDIUM 7.5 HIGH
An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI.
CVE-2019-12524 3 Canonical, Debian, Squid-cache 3 Ubuntu Linux, Debian Linux, Squid 2021-02-09 7.5 HIGH 9.8 CRITICAL
An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.