Multiple use-after-free vulnerabilities in the (1) htmlPArsePubidLiteral and (2) htmlParseSystemiteral functions in libxml2 before 2.9.4, as

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• apple iphone osbefore 9.3.2
• apple mac os xbefore 10.11.5
• apple tvosbefore 9.2.1
• apple watchosbefore 2.2.1
• canonical ubuntu linux12.04
• canonical ubuntu linux14.04
• canonical ubuntu linux15.10
• canonical ubuntu linux16.04
• debian debian linux8.0
• mcafee web gateway7.6.0.0 and later · up to 7.6.2.3 inclusive
• mcafee web gateway7.5.0.0 and later · up to 7.5.2.10 inclusive
• redhat enterprise linux desktop6.0
• redhat enterprise linux desktop7.0
• redhat enterprise linux server6.0
• redhat enterprise linux server7.0
• redhat enterprise linux server aus7.2
• redhat enterprise linux server aus7.3
• redhat enterprise linux server aus7.4
• redhat enterprise linux server aus7.6
• redhat enterprise linux server eus7.2

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Other highest-scoring records for the same primary product.

• CVE-2021-3493The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities KEV
  76This week
• CVE-2017-14492Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via
  67This week
• CVE-2017-14493Stack-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code vi
  64This week
• CVE-2016-4553client_side.cc in Squid before 3.5.18 and 4.x before 4.0.10 does not properly ignore the Host header when absolute-URI is provided, which al
  58Plan
• CVE-2017-14495Memory leak in dnsmasq before 2.78, when the --add-mac, --add-cpe-id or --add-subnet option is specified, allows remote attackers to cause a
  55Plan
• CVE-2016-4054Buffer overflow in Squid 3.x before 3.5.17 and 4.x before 4.0.9 allows remote attackers to execute arbitrary code via crafted Edge Side Incl
  55Plan

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1free(dev->buf);2/* ... another thread is still running ... */3process(dev->buf);

1lock(&dev->lock);2free(dev->buf);3dev->buf = NULL;4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.