A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1, 17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the creation of the dialog object, and its next use by the thread that created it. Depending on some off-nominal circumstances and timing, it was possible for another thread to free said dialog in this gap. Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client must be authenticated, or Asterisk must be configured for anonymous calling.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1,     17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new     SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the     creation of the dialog object, and its next use by the thread that created it. Depending on some off-     nominal circumstances and timing, it was possible for another thread to free said dialog in this gap.
    Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or     accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a     connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client     must be authenticated, or Asterisk must be configured for anonymous calling. (CVE-2020-28327)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1,
    17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new
    SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the
    creation of the dialog object, and its next use by the thread that created it. Depending on some off-
    nominal circumstances and timing, it was possible for another thread to free said dialog in this gap.
    Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or
    accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a
    connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client
    must be authenticated, or Asterisk must be configured for anonymous calling. (CVE-2020-28327)

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before
    18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote
    response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened,
    and the remote responded with a declined T.38 stream, then Asterisk would crash. (CVE-2021-26717)

  - A res_pjsip_session crash was discovered in Asterisk Open Source 13.x before 13.37.1, 16.x before 16.14.1,
    17.x before 17.8.1, and 18.x before 18.0.1. and Certified Asterisk before 16.8-cert5. Upon receiving a new
    SIP Invite, Asterisk did not return the created dialog locked or referenced. This caused a gap between the
    creation of the dialog object, and its next use by the thread that created it. Depending on some off-
    nominal circumstances and timing, it was possible for another thread to free said dialog in this gap.
    Asterisk could then crash when the dialog object, or any of its dependent objects, were dereferenced or
    accessed next by the initial-creation thread. Note, however, that this crash can only occur when using a
    connection-oriented protocol (e.g., TCP or TLS, but not UDP) for SIP transport. Also, the remote client
    must be authenticated, or Asterisk must be configured for anonymous calling. (CVE-2020-28327)

  - An issue was discovered in res_pjsip_diversion.c in Sangoma Asterisk before 13.38.0, 14.x through 16.x
    before 16.15.0, 17.x before 17.9.0, and 18.x before 18.1.0. A crash can occur when a SIP message is
    received with a History-Info header that contains a tel-uri, or when a SIP 181 response is received that
    contains a tel-uri in the Diversion header. (CVE-2020-35652)

  - A buffer overflow in res_pjsip_diversion.c in Sangoma Asterisk versions 13.38.1, 16.15.1, 17.9.1, and
    18.1.1 allows remote attacker to crash Asterisk by deliberately misusing SIP 181 responses.
    (CVE-2020-35776)

  - Incorrect access controls in res_srtp.c in Sangoma Asterisk 13.38.1, 16.16.0, 17.9.1, and 18.2.0 and
    Certified Asterisk 16.8-cert5 allow a remote unauthenticated attacker to prematurely terminate secure
    calls by replaying SRTP packets. (CVE-2021-26712)

ID	Name	Product	Family	Severity
252371	Linux Distros Unpatched Vulnerability : CVE-2020-28327	Nessus	Misc.	medium
423669	Alpine: multiple asterisk packages: security update to 18.0.1-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	medium
423669	Alpine: multiple asterisk packages: security update to 18.0.1-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	medium
403578	Alpine: asterisk: security update to 16.14.1-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	medium
403578	Alpine: asterisk: security update to 16.14.1-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	medium
400268	Alpine: multiple asterisk packages: security update to 18.1.1-r0 (deprecated)	Tenable Cloud Security	Alpine Linux Local Security Checks	high
400268	Alpine: multiple asterisk packages: security update to 18.1.1-r0 (deprecated)	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	high

Detections

Analytics

CVE-2020-28327

medium

Tenable Plugins

medium

medium

medium

medium

medium

high

high