The version of unbound installed on the remote host is prior to 1.7.3-15. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1683 advisory.

  - Unbound before 1.9.5 allows an integer overflow in the regional allocator via regional_alloc. NOTE: The     vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound     installation cannot be remotely or locally exploited (CVE-2019-25032)

  - Unbound before 1.9.5 allows an integer overflow in the regional allocator via the ALIGN_UP macro. NOTE:
    The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound     installation cannot be remotely or locally exploited (CVE-2019-25033)

  - Unbound before 1.9.5 allows an integer overflow in sldns_str2wire_dname_buf_origin, leading to an out-of-     bounds write. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable,     a running Unbound installation cannot be remotely or locally exploited (CVE-2019-25034)

  - Unbound before 1.9.5 allows an out-of-bounds write in sldns_bget_token_par. NOTE: The vendor disputes that     this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be     remotely or locally exploited (CVE-2019-25035)

  - Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname. NOTE: The vendor     disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation     cannot be remotely or locally exploited (CVE-2019-25036)

  - Unbound before 1.9.5 allows an assertion failure and denial of service in dname_pkt_copy via an invalid     packet. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a     running Unbound installation cannot be remotely or locally exploited (CVE-2019-25037)

  - Unbound before 1.9.5 allows an integer overflow in a size calculation in dnscrypt/dnscrypt.c. NOTE: The     vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound     installation cannot be remotely or locally exploited (CVE-2019-25038)

  - Unbound before 1.9.5 allows an integer overflow in a size calculation in respip/respip.c. NOTE: The vendor     disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation     cannot be remotely or locally exploited (CVE-2019-25039)

  - Unbound before 1.9.5 allows an infinite loop via a compressed name in dname_pkt_copy. NOTE: The vendor     disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation     cannot be remotely or locally exploited (CVE-2019-25040)

  - Unbound before 1.9.5 allows an assertion failure via a compressed name in dname_pkt_copy. NOTE: The vendor     disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation     cannot be remotely or locally exploited (CVE-2019-25041)

  - Unbound before 1.9.5 allows an out-of-bounds write via a compressed name in rdata_copy. NOTE: The vendor     disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation     cannot be remotely or locally exploited (CVE-2019-25042)

  - NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version     4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID     file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case     the file was already present, they would follow symlinks if the file happened to be a symlink instead of a     regular file. An additional chown of the file would then take place after it was written, making the user     Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user     Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would     like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root     privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability     that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker     having access to the limited permission user Unbound/NSD runs as and point through the symlink to a     critical file on the system. (CVE-2020-28935)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

Analytics

Amazon Linux 2 : unbound (ALAS-2021-1683)

critical Nessus Plugin ID 151275

Version 1.2