CVE-2019-12521

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.

Squid is a high-performance proxy caching server. It handles all requests in a single, non-blocking, I/O-driven process and keeps meta data and implements negative caching of failed requests.

Security Fix(es):

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-2019-12521)

Squid is a high-performance proxy caching server for web clients, supporting FTP, Gopher, and HTTP data objects.

The following packages have been upgraded to a later upstream version: squid (4.11). (BZ#1829467)

Security Fix(es):

• squid: Improper input validation in request allows for proxy manipulation (CVE-2019-12520)

• squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash (CVE-2019-12521)

• squid: Improper input validation in URI processor (CVE-2019-12523)

• squid: Improper access restriction in url_regex may lead to security bypass (CVE-2019-12524)

• squid: Heap overflow issue in URN processing (CVE-2019-12526)

• squid: Information Disclosure issue in FTP Gateway (CVE-2019-12528)

• squid: Out of bounds read in Proxy-Authorization header causes DoS (CVE-2019-12529)

• squid: Denial of service in cachemgr.cgi (CVE-2019-12854)

• squid: Buffer overflow in URI processor (CVE-2019-18676)

• squid: Cross-Site Request Forgery issue in HTTP Request processing (CVE-2019-18677)

• squid: HTTP Request Splitting issue in HTTP message processing (CVE-2019-18678)

• squid: Information Disclosure issue in HTTP Digest Authentication (CVE-2019-18679)

• squid: Mishandled HTML in the host parameter to cachemgr.cgi results in insecure behaviour (CVE-2019-18860)

• squid: Improper input validation issues in HTTP Request processing (CVE-2020-8449)

• squid: Buffer overflow in reverse-proxy configurations (CVE-2020-8450)

• squid: DoS in TLS handshake (CVE-2020-14058)

• squid: Request smuggling and poisoning attack against the HTTP cache (CVE-2020-15049)

• squid: Improper input validation could result in a DoS (CVE-2020-24606)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.3 Release Notes linked from the References section.

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.

Squid is a high-performance proxy caching server for web clients, supporting FTP, Gopher, and HTTP data objects.

The following packages have been upgraded to a later upstream version: squid (4.11). (BZ#1829467)

Security Fix(es):

• squid: Improper input validation in request allows for proxy manipulation (CVE-2019-12520)

• squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash (CVE-2019-12521)

• squid: Improper input validation in URI processor (CVE-2019-12523)

• squid: Improper access restriction in url_regex may lead to security bypass (CVE-2019-12524)

• squid: Heap overflow issue in URN processing (CVE-2019-12526)

• squid: Information Disclosure issue in FTP Gateway (CVE-2019-12528)

• squid: Out of bounds read in Proxy-Authorization header causes DoS (CVE-2019-12529)

• squid: Denial of service in cachemgr.cgi (CVE-2019-12854)

• squid: Buffer overflow in URI processor (CVE-2019-18676)

• squid: Cross-Site Request Forgery issue in HTTP Request processing (CVE-2019-18677)

• squid: HTTP Request Splitting issue in HTTP message processing (CVE-2019-18678)

• squid: Information Disclosure issue in HTTP Digest Authentication (CVE-2019-18679)

• squid: Mishandled HTML in the host parameter to cachemgr.cgi results in insecure behaviour (CVE-2019-18860)

• squid: Improper input validation issues in HTTP Request processing (CVE-2020-8449)

• squid: Buffer overflow in reverse-proxy configurations (CVE-2020-8450)

• squid: DoS in TLS handshake (CVE-2020-14058)

• squid: Request smuggling and poisoning attack against the HTTP cache (CVE-2020-15049)

• squid: Improper input validation could result in a DoS (CVE-2020-24606)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

• CVE-2019-12521: fix ESI parser off-by-one heap overflow by enforcing a stack-depth limit and throwing on overflow
• CVE-2019-12524 already addressed by the CVE-2019-12520 backport (same fix upstream; see Squid advisory SQUID-2019:4)

• CVE-2019-12521: fix ESI parser off-by-one heap overflow by enforcing a stack-depth limit and throwing on overflow
• CVE-2019-12524 already addressed by the CVE-2019-12520 backport (same fix upstream; see Squid advisory SQUID-2019:4)

This update for squid to version 4.11 fixes the following issues:

• CVE-2020-11945: Fixed a potential remote code execution vulnerability when using HTTP Digest Authentication (bsc#1170313).
• CVE-2019-12519, CVE-2019-12521: Fixed incorrect buffer handling that can result in cache poisoning, remote execution, and denial of service attacks when processing ESI responses (bsc#1169659).
• CVE-2020-8517: Fixed a possible denial of service caused by incorrect buffer management ext_lm_group_acl when processing NTLM Authentication credentials (bsc#1162691).
• CVE-2019-12528: Fixed possible information disclosure when translating FTP server listings into HTTP responses (bsc#1162689).
• CVE-2019-18860: Fixed handling of invalid domain names in cachemgr.cgi (bsc#1167373).

This update was imported from the SUSE:SLE-15:Update update project.

This update for squid to version 4.11 fixes the following issues:

• CVE-2020-11945: Fixed a potential remote code execution vulnerability when using HTTP Digest Authentication (bsc#1170313).
• CVE-2019-12519, CVE-2019-12521: Fixed incorrect buffer handling that can result in cache poisoning, remote execution, and denial of service attacks when processing ESI responses (bsc#1169659).
• CVE-2020-8517: Fixed a possible denial of service caused by incorrect buffer management ext_lm_group_acl when processing NTLM Authentication credentials (bsc#1162691).
• CVE-2019-12528: Fixed possible information disclosure when translating FTP server listings into HTTP responses (bsc#1162689).
• CVE-2019-18860: Fixed handling of invalid domain names in cachemgr.cgi (bsc#1167373).

This update for squid to version 4.11 fixes the following issues:

• CVE-2020-11945: Fixed a potential remote code execution vulnerability when using HTTP Digest Authentication (bsc#1170313).
• CVE-2019-12519, CVE-2019-12521: Fixed incorrect buffer handling that can result in cache poisoning, remote execution, and denial of service attacks when processing ESI responses (bsc#1169659).
• CVE-2020-8517: Fixed a possible denial of service caused by incorrect buffer management ext_lm_group_acl when processing NTLM Authentication credentials (bsc#1162691).
• CVE-2019-12528: Fixed possible information disclosure when translating FTP server listings into HTTP responses (bsc#1162689).
• CVE-2019-18860: Fixed handling of invalid domain names in cachemgr.cgi (bsc#1167373).

This update for squid fixes the following issues:

• CVE-2019-12519, CVE-2019-12521: fixes incorrect buffer handling that can result in cache poisoning, remote execution, and denial of service attacks when processing ESI responses (bsc#1169659).
• CVE-2020-11945: fixes a potential remote execution vulnerability when using HTTP Digest Authentication (bsc#1170313).
• CVE-2019-12520, CVE-2019-12524: fixes a potential ACL bypass, cache-bypass and cross-site scripting attack when processing invalid HTTP Request messages (bsc#1170423).

This update for squid3 fixes the following issues:

• Fixed a Cache Poisoning and Request Smuggling attack (CVE-2020-15049, bsc#1173455)

• Fixed incorrect buffer handling that can result in cache poisoning, remote execution, and denial of service attacks when processing ESI responses (CVE-2019-12519, CVE-2019-12521, bsc#1169659)

• Fixed handling of hostname in cachemgr.cgi (CVE-2019-18860, bsc#1167373)

• Fixed a potential remote execution vulnerability when using HTTP Digest Authentication (CVE-2020-11945, bsc#1170313)

• Fixed a potential ACL bypass, cache-bypass and cross-site scripting attack when processing invalid HTTP Request messages (CVE-2019-12520, CVE-2019-12524, bsc#1170423)

• Fixed a potential denial of service when processing TLS certificates during HTTPS connections (CVE-2020-14059, bsc#1173304)

• Fixed a potential denial of service associated with incorrect buffer management of HTTP Basic Authentication credentials (bsc#1141329, CVE-2019-12529)

• Fixed an incorrect buffer management resulting in vulnerability to a denial of service during processing of HTTP Digest Authentication credentials (bsc#1141332, CVE-2019-12525)

• Fix XSS via user_name or auth parameter in cachemgr.cgi (bsc#1140738, CVE-2019-13345)

• Fixed a potential code execution vulnerability (CVE-2019-12526, bsc#1156326)

• Fixed HTTP Request Splitting in HTTP message processing and information disclosure in HTTP Digest Authentication (CVE-2019-18678, CVE-2019-18679, bsc#1156323, bsc#1156324)

• Fixed a security issue allowing a remote client ability to cause use a buffer overflow when squid is acting as reverse-proxy. (CVE-2020-8449, CVE-2020-8450, bsc#1162687)

• Fixed a security issue allowing for information disclosure in FTP gateway (CVE-2019-12528, bsc#1162689)

• Fixed a security issue in ext_lm_group_acl when processing NTLM Authentication credentials. (CVE-2020-8517, bsc#1162691)

• Fixed Cross-Site Request Forgery in HTTP Request processing (CVE-2019-18677, bsc#1156328)

• Disable urn parsing and parsing of unknown schemes (bsc#1156329, CVE-2019-12523, CVE-2019-18676)

Jeriko One discovered that Squid incorrectly handled certain Edge Side Includes (ESI) responses. A malicious remote server could cause Squid to crash, possibly poison the cache, or possibly execute arbitrary code. (CVE-2019-12519, CVE-2019-12521)

It was discovered that Squid incorrectly handled the hostname parameter to cachemgr.cgi when certain browsers are used. A remote attacker could possibly use this issue to inject HTML or invalid characters in the hostname parameter. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 19.10. (CVE-2019-18860)

Clément Berthaux and Florian Guilbert discovered that Squid incorrectly handled Digest Authentication nonce values. A remote attacker could use this issue to replay nonce values, or possibly execute arbitrary code. (CVE-2020-11945)