cbcvebase.
CVE-2019-11704
published 2019-07-23

CVE-2019-11704: A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in icalmemory_strdup_and_dequote when processing certain email messages, resulting…

PriorityP261critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EXPLOIT
EPSS
10.53%
95.2th percentile
A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in icalmemory_strdup_and_dequote when processing certain email messages, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.7.1.

Affected

7 ranges
VendorProductVersion rangeFixed in
debianthunderbird< thunderbird 1:60.7.1-1 (bookworm)thunderbird 1:60.7.1-1 (bookworm)
mozillathunderbird< 60.7.160.7.1
mozillathunderbird>= 0 < 1:60.7.1-11:60.7.1-1
mozillathunderbird>= 0 < 1:60.7.1-11:60.7.1-1
mozillathunderbird>= 0 < 1:60.7.1-11:60.7.1-1
mozillathunderbird>= 0 < 1:60.7.1-11:60.7.1-1
mozillathunderbird>= unspecified < 60.7.160.7.1

Detection & IOCsextracted from sources · hover to see the quote

urlhttps://github.com/x41sec/advisories/tree/master/X41-2019-001
urlhttps://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/47002.zip
pathicalvalue.c
commandcalendar.icaljs = true
  • No user interaction is required; the vulnerability can be triggered purely by receiving a specially crafted calendar attachment, making it suitable for detection at the mail gateway/MTA level by inspecting iCal attachments for strings ending with a backslash before a field terminator
  • Monitor for Thunderbird process crashes (heap corruption) coinciding with receipt of email containing iCal/calendar MIME attachments (Content-Type: text/calendar or application/ics)
  • ·Setting calendar.icaljs = true in Thunderbird preferences switches the iCal parser from the vulnerable libical (C) to icaljs (JavaScript), fully mitigating this vulnerability without requiring a patch
  • ·The vulnerable code originates from a fork of upstream libical version 0.47; upstream fixed this in v1.0.0 (commit a4230eb8) but the fix was never backported to Thunderbird's bundled copy until ESR 60.7.1

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
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