{
  "threat_severity" : "Moderate",
  "public_date" : "2020-04-24T00:00:00Z",
  "bugzilla" : {
    "description" : "squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash",
    "id" : "1827562",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=1827562"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.9",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-122",
  "details" : [ "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.", "A flaw was found in squid. 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." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2020-11-04T00:00:00Z",
    "advisory" : "RHSA-2020:4743",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8",
    "package" : "squid:4-8030020200828070549.30b713e6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 5",
    "fix_state" : "Out of support scope",
    "package_name" : "squid",
    "cpe" : "cpe:/o:redhat:enterprise_linux:5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "squid",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "squid34",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Will not fix",
    "package_name" : "squid",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2019-12521\nhttps://nvd.nist.gov/vuln/detail/CVE-2019-12521\nhttp://www.squid-cache.org/Advisories/SQUID-2019_12.txt" ],
  "name" : "CVE-2019-12521",
  "csaw" : false
}