CVE-2019-15680

TightVNC code version 1.3.10 contains null pointer dereference in HandleZlibBPP function, which results Denial of System (DoS). This attack appear to be exploitable via network connectivity.

From the Ubuntu Security Team

Pavel Cheremushkin discovered that TightVNC has a null pointer dereference vulnerability. An attacker could use it to cause a Denial of Service or possible a remote code execution.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libvncserver	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Not affected
	20.04 LTS focal	Fixed 0.9.12+dfsg-9ubuntu0.1
	19.10 eoan	Fixed 0.9.11+dfsg-1.3ubuntu0.1
	19.04 disco	Ignored
	18.04 LTS bionic	Fixed 0.9.11+dfsg-1ubuntu1.2
	16.04 LTS xenial	Fixed 0.9.10+dfsg-3ubuntu0.16.04.4
	14.04 LTS trusty	Not in release
ssvnc	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.10 groovy	Ignored
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Not in release
tightvnc	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.10 groovy	Ignored
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Fixed 1.3.9-6.5+deb8u1build0.14.04.1~esm1 Ubuntu Pro
veyon	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.10 groovy	Ignored
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.04 LTS bionic	Not in release
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release
vncsnapshot	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.10 groovy	Ignored
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Not in release
x11vnc	24.04 LTS noble	Needs evaluation
	23.10 mantic	Ignored
	23.04 lunar	Ignored
	22.10 kinetic	Ignored
	22.04 LTS jammy	Needs evaluation
	21.10 impish	Ignored
	21.04 hirsute	Ignored
	20.10 groovy	Ignored
	20.04 LTS focal	Needs evaluation
	19.10 eoan	Ignored
	19.04 disco	Ignored
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Needs evaluation

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Notes

mdeslaur

per upstream, this is a non-issue in libvncserver as checks are already done in zlib, see: https://github.com/LibVNC/libvncserver/issues/359#issuecomment-599133529 for completeness, the fix was added to focal and earlier releases, but will not be added to groovy+

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libvncserver	Upstream: 85d0005

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-4407-1
LibVNCServer vulnerabilities
1 July 2020