The snmp_pdu_parse function in snmp_api.c in net-snmp 5.7.2 and earlier does not remove the varBind variable in a netsnmp_variable_list item when parsing of the SNMP PDU fails, which allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted packet.

References

• https://nvd.nist.gov/vuln/detail/CVE-2015-5621
• https://bugzilla.redhat.com/show_bug.cgi?id=1212408
• https://cert-portal.siemens.com/productcert/pdf/ssa-978220.pdf
• https://www.debian.org/security/2018/dsa-4154
• http://lists.opensuse.org/opensuse-updates/2015-09/msg00004.html
• http://rhn.redhat.com/errata/RHSA-2015-1636.html
• http://support.citrix.com/article/CTX209443
• http://www.openwall.com/lists/oss-security/2015/04/13/1
• http://www.openwall.com/lists/oss-security/2015/04/16/15
• http://www.openwall.com/lists/oss-security/2015/07/31/1
• http://www.securityfocus.com/bid/76380
• http://www.securitytracker.com/id/1033304
• http://www.ubuntu.com/usn/USN-2711-1
• https://sourceforge.net/p/net-snmp/bugs/2615
• https://www.exploit-db.com/exploits/45547
• http://sourceforge.net/p/net-snmp/code/ci/f23bcd3ac6ddee5d0a48f9703007ccc738914791