[Pkg-tigervnc-devel] Bug#947428: tigervnc: CVE-2019-15691 CVE-2019-15692 CVE-2019-15693 CVE-2019-15694 CVE-2019-15695

[Salvatore Bonaccorso]

Source: tigervnc
Version: 1.9.0+dfsg-4
Severity: grave
Tags: security upstream
Control: found -1 1.9.0+dfsg-3

Hi,

The following vulnerabilities were published for tigervnc.

CVE-2019-15691[0]:
| TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-
| return, which occurs due to incorrect usage of stack memory in
| ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder
| may try to access stack variable, which has been already freed during
| the process of stack unwinding. Exploitation of this vulnerability
| could potentially result into remote code execution. This attack
| appear to be exploitable via network connectivity.


CVE-2019-15692[1]:
| TigerVNC version prior to 1.10.1 is vulnerable to heap buffer
| overflow. Vulnerability could be triggered from CopyRectDecoder due to
| incorrect value checks. Exploitation of this vulnerability could
| potentially result into remote code execution. This attack appear to
| be exploitable via network connectivity.


CVE-2019-15693[2]:
| TigerVNC version prior to 1.10.1 is vulnerable to heap buffer
| overflow, which occurs in TightDecoder::FilterGradient. Exploitation
| of this vulnerability could potentially result into remote code
| execution. This attack appear to be exploitable via network
| connectivity.


CVE-2019-15694[3]:
| TigerVNC version prior to 1.10.1 is vulnerable to heap buffer
| overflow, which could be triggered from DecodeManager::decodeRect.
| Vulnerability occurs due to the signdness error in processing
| MemOutStream. Exploitation of this vulnerability could potentially
| result into remote code execution. This attack appear to be
| exploitable via network connectivity.


CVE-2019-15695[4]:
| TigerVNC version prior to 1.10.1 is vulnerable to stack buffer
| overflow, which could be triggered from CMsgReader::readSetCursor.
| This vulnerability occurs due to insufficient sanitization of
| PixelFormat. Since remote attacker can choose offset from start of the
| buffer to start writing his values, exploitation of this vulnerability
| could potentially result into remote code execution. This attack
| appear to be exploitable via network connectivity.


If you fix the vulnerabilities please also make sure to include the
CVE (Common Vulnerabilities & Exposures) ids in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2019-15691
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15691
[1] https://security-tracker.debian.org/tracker/CVE-2019-15692
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15692
[2] https://security-tracker.debian.org/tracker/CVE-2019-15693
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15693
[3] https://security-tracker.debian.org/tracker/CVE-2019-15694
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15694
[4] https://security-tracker.debian.org/tracker/CVE-2019-15695
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15695

Please adjust the affected versions in the BTS as needed.



-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.3.0-3-amd64 (SMP w/2 CPU cores)
Kernel taint flags: TAINT_WARN
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled