An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c.

The remote Redhat Enterprise Linux 6 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - libvncserver: Improper input sanitization in rfbProcessClientNormalMessage in rfbserver.c (CVE-2018-7225)

  - Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote     servers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted     FramebufferUpdate message containing a subrectangle outside of the client drawing area. (CVE-2016-9941)

  - Heap-based buffer overflow in ultra.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers     to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted     FramebufferUpdate message with the Ultra type tile, such that the LZO payload decompressed length exceeds     what is specified by the tile dimensions. (CVE-2016-9942)

  - LibVNC before commit 502821828ed00b4a2c4bef90683d0fd88ce495de contains heap out-of-bound write     vulnerability in server code of file transfer extension that can result remote code execution     (CVE-2018-15127)

  - LibVNC before commit a83439b9fbe0f03c48eb94ed05729cb016f8b72f contains multiple heap out-of-bound write     vulnerabilities in VNC client code that can result remote code execution (CVE-2018-20019)

  - LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write     vulnerability inside structure in VNC client code that can result remote code execution (CVE-2018-20020)

  - LibVNC before 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 contains multiple weaknesses CWE-665: Improper     Initialization vulnerability in VNC client code that allows attacker to read stack memory and can be abuse     for information disclosure. Combined with another vulnerability, it can be used to leak stack memory     layout and in bypassing ASLR (CVE-2018-20022)

  - LibVNC before commit 4a21bbd097ef7c44bb000c3bd0907f96a10e4ce7 contains null pointer dereference in VNC     client code that can result DoS. (CVE-2018-20024)

  - LibVNC before 0.9.12 contains multiple heap out-of-bounds write vulnerabilities in     libvncclient/rfbproto.c. The fix for CVE-2018-20019 was incomplete. (CVE-2018-20748)

  - LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The     fix for CVE-2018-15127 was incomplete. (CVE-2018-20749)

  - LibVNC through 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The     fix for CVE-2018-15127 was incomplete. (CVE-2018-20750)

  - LibVNC commit before d01e1bb4246323ba6fcee3b82ef1faa9b1dac82a contains a memory leak (CWE-655) in VNC     server code, which allow an attacker to read stack memory and can be abused for information disclosure.
    Combined with another vulnerability, it can be used to leak stack memory and bypass ASLR. This attack     appear to be exploitable via network connectivity. These vulnerabilities have been fixed in commit     d01e1bb4246323ba6fcee3b82ef1faa9b1dac82a. (CVE-2019-15681)

  - libvncserver: HandleCursorShape() integer overflow resulting in heap-based buffer overflow     (CVE-2019-15690)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rfbregion.c has a NULL pointer     dereference. (CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an     infinite loop in libvncclient/sockets.c. (CVE-2020-14398)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/scale.c has a pixel_value integer     overflow. (CVE-2020-14401)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/corre.c allows out-of-bounds access     via encodings. (CVE-2020-14402)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/hextile.c allows out-of-bounds access     via encodings. (CVE-2020-14403)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rre.c allows out-of-bounds access via     encodings. (CVE-2020-14404)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncclient/rfbproto.c does not limit TextChat     size. (CVE-2020-14405)

  - A divide by zero issue was found to occur in libvncserver-0.9.12. A malicious client could use this flaw     to send a specially crafted message that, when processed by the VNC server, would lead to a floating point     exception, resulting in a denial of service. (CVE-2020-25708)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

The remote SUSE Linux SLES11 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2020:14424-1 advisory.

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/rfbregion.c has a NULL pointer     dereference. (CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an     infinite loop in libvncclient/sockets.c. (CVE-2020-14398)

  - ** DISPUTED ** An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed     through uint32_t pointers in libvncclient/rfbproto.c. NOTE: there is reportedly no trust boundary     crossed. (CVE-2020-14399)

  - ** DISPUTED ** An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed     through uint16_t pointers in libvncserver/translate.c. NOTE: Third parties do not consider this to be a     vulnerability as there is no known path of exploitation or cross of a trust boundary. (CVE-2020-14400)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/scale.c has a pixel_value integer     overflow. (CVE-2020-14401)

  - An issue was discovered in LibVNCServer before 0.9.13. libvncserver/corre.c allows out-of-bounds access     via encodings. (CVE-2020-14402)

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

According to the versions of the libvncserver package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in LibVNCServer before 0.9.13.
    There is an information leak (of uninitialized memory     contents) in the libvncclient/rfbproto.c     ConnectToRFBRepeater function.(CVE-2018-21247)

  - libvncclient/sockets.c in LibVNCServer before 0.9.13     has a buffer overflow via a long socket     filename.(CVE-2019-20839)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rfbregion.c has a NULL pointer     dereference.(CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13.
    An improperly closed TCP connection causes an infinite     loop in libvncclient/sockets.c.(CVE-2020-14398)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint32_t pointers     in libvncclient/rfbproto.c.(CVE-2020-14399)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint16_t pointers     in libvncserver/translate.c.(CVE-2020-14400)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/scale.c has a pixel_value integer     overflow.(CVE-2020-14401)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/corre.c allows out-of-bounds access via     encodings.(CVE-2020-14402)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/hextile.c allows out-of-bounds access via     encodings.(CVE-2020-14403)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rre.c allows out-of-bounds access via     encodings.(CVE-2020-14404)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncclient/rfbproto.c does not limit TextChat     size.(CVE-2020-14405)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the libvncserver package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - LibVNCServer makes writing a VNC server (or more     correctly, a program exporting a frame-buffer via the     Remote Frame Buffer protocol) easy. It hides the     programmer from the tedious task of managing clients     and compression schemata.Security Fix(es):An issue was     discovered in LibVNCServer before 0.9.13. There is an     information leak (of uninitialized memory contents) in     the libvncclient/rfbproto.c ConnectToRFBRepeater     function.(CVE-2018-21247)libvncclient/sockets.c in     LibVNCServer before 0.9.13 has a buffer overflow via a     long socket filename.(CVE-2019-20839)An issue was     discovered in LibVNCServer before 0.9.13.
    libvncserver/rfbregion.c has a NULL pointer     dereference.(CVE-2020-14397)An issue was discovered in     LibVNCServer before 0.9.13. An improperly closed TCP     connection causes an infinite loop in     libvncclient/sockets.c.(CVE-2020-14398)An issue was     discovered in LibVNCServer before 0.9.13. Byte-aligned     data is accessed through uint32_t pointers in     libvncclient/rfbproto.c. NOTE: there is reportedly 'no     trust boundary crossed.'(CVE-2020-14399)An issue was     discovered in LibVNCServer before 0.9.13. Byte-aligned     data is accessed through uint16_t pointers in     libvncserver/translate.c. NOTE: Third parties do not     consider this to be a vulnerability as there is no     known path of exploitation or cross of a trust     boundary.(CVE-2020-14400)An issue was discovered in     LibVNCServer before 0.9.13. libvncserver/scale.c has a     pixel_value integer overflow.(CVE-2020-14401)An issue     was discovered in LibVNCServer before 0.9.13.
    libvncserver/corre.c allows out-of-bounds access via     encodings.(CVE-2020-14402)An issue was discovered in     LibVNCServer before 0.9.13. libvncserver/hextile.c     allows out-of-bounds access via     encodings.(CVE-2020-14403)An issue was discovered in     LibVNCServer before 0.9.13. libvncserver/rre.c allows     out-of-bounds access via encodings.(CVE-2020-14404)An     issue was discovered in LibVNCServer before 0.9.13.
    libvncclient/rfbproto.c does not limit TextChat     size.(CVE-2020-14405)libvncclient/cursor.c in     LibVNCServer through 0.9.12 has a HandleCursorShape     integer overflow and heap-based buffer overflow via a     large height or width value. (CVE-2019-20788)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the libvncserve packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in LibVNCServer before 0.9.13.
    There is an information leak (of uninitialized memory     contents) in the libvncclient/rfbproto.c     ConnectToRFBRepeater function.(CVE-2018-21247)

  - libvncclient/sockets.c in LibVNCServer before 0.9.13     has a buffer overflow via a long socket     filename.(CVE-2019-20839)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rfbregion.c has a NULL pointer     dereference.(CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13.
    An improperly closed TCP connection causes an infinite     loop in libvncclient/sockets.c.(CVE-2020-14398)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint32_t pointers     in libvncclient/rfbproto.c.(CVE-2020-14399)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint16_t pointers     in libvncserver/translate.c.(CVE-2020-14400)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/scale.c has a pixel_value integer     overflow.(CVE-2020-14401)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/corre.c allows out-of-bounds access via     encodings.(CVE-2020-14402)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/hextile.c allows out-of-bounds access via     encodings.(CVE-2020-14403)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rre.c allows out-of-bounds access via     encodings.(CVE-2020-14404)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncclient/rfbproto.c does not limit TextChat     size.(CVE-2020-14405)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for LibVNCServer fixes the following issues :

security update fix CVE-2018-21247 [bsc#1173874], uninitialized memory contents are vulnerable to Information leak fix CVE-2019-20839 [bsc#1173875], buffer overflow in ConnectClientToUnixSock() fix CVE-2019-20840 [bsc#1173876], unaligned accesses in hybiReadAndDecode can lead to denial of service fix CVE-2020-14398 [bsc#1173880], improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c fix CVE-2020-14397 [bsc#1173700], NULL pointer dereference in libvncserver/rfbregion.c fix CVE-2020-14399 [bsc#1173743], Byte-aligned data is accessed through uint32_t pointers in libvncclient/rfbproto.c. fix CVE-2020-14400 [bsc#1173691], Byte-aligned data is accessed through uint16_t pointers in libvncserver/translate.c. fix CVE-2020-14401 [bsc#1173694], potential integer overflows in libvncserver/scale.c fix CVE-2020-14402 [bsc#1173701], out-of-bounds access via encodings. fix CVE-2020-14403 [bsc#1173701], out-of-bounds access via encodings. fix CVE-2020-14404 [bsc#1173701], out-of-bounds access via encodings. fix CVE-2017-18922 [bsc#1173477], preauth buffer overwrite

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the libvncserver package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/hextile.c allows out-of-bounds access via     encodings.(CVE-2020-14403)

  - An issue was discovered in LibVNCServer before 0.9.13.
    An improperly closed TCP connection causes an infinite     loop in libvncclient/sockets.c.(CVE-2020-14398)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/scale.c has a pixel_value integer     overflow.(CVE-2020-14401)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/corre.c allows out-of-bounds access via     encodings.(CVE-2020-14402)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint16_t pointers     in libvncserver/translate.c.(CVE-2020-14400)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rre.c allows out-of-bounds access via     encodings.(CVE-2020-14404)

  - An issue was discovered in LibVNCServer before 0.9.13.
    There is an information leak (of uninitialized memory     contents) in the libvncclient/rfbproto.c     ConnectToRFBRepeater function.(CVE-2018-21247)

  - libvncclient/sockets.c in LibVNCServer before 0.9.13     has a buffer overflow via a long socket     filename.(CVE-2019-20839)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncclient/rfbproto.c does not limit TextChat     size.(CVE-2020-14405)

  - An issue was discovered in LibVNCServer before 0.9.13.
    libvncserver/rfbregion.c has a NULL pointer     dereference.(CVE-2020-14397)

  - An issue was discovered in LibVNCServer before 0.9.13.
    Byte-aligned data is accessed through uint32_t pointers     in libvncclient/rfbproto.c.(CVE-2020-14399)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Ramin Farajpour Cami discovered that LibVNCServer incorrectly handled certain malformed unix socket names. A remote attacker could exploit this with a crafted socket name, leading to a denial of service, or possibly execute arbitrary code. (CVE-2019-20839) It was discovered that LibVNCServer did not properly access byte-aligned data. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. (CVE-2019-20840) Christian Beier discovered that LibVNCServer incorrectly handled anonymous TLS connections. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2020-14396) It was discovered that LibVNCServer incorrectly handled region clipping. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. (CVE-2020-14397) It was discovered that LibVNCServer did not properly reset incorrectly terminated TCP connections. A remote attacker could possibly use this issue to cause an infinite loop, resulting in a denial of service. (CVE-2020-14398) It was discovered that LibVNCServer did not properly access byte-aligned data. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service.
(CVE-2020-14399, CVE-2020-14400) It was discovered that LibVNCServer incorrectly handled screen scaling on the server side. A remote attacker could use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2020-14401) It was discovered that LibVNCServer incorrectly handled encodings. A remote attacker could use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-14402, CVE-2020-14403, CVE-2020-14404) It was discovered that LibVNCServer incorrectly handled TextChat messages. A remote attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. (CVE-2020-14405).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for LibVNCServer fixes the following issues :

  - security update

  - added patches fix CVE-2018-21247 [bsc#1173874],     uninitialized memory contents are vulnerable to     Information leak

  + LibVNCServer-CVE-2018-21247.patch fix CVE-2019-20839     [bsc#1173875], buffer overflow in     ConnectClientToUnixSock()

  + LibVNCServer-CVE-2019-20839.patch fix CVE-2019-20840     [bsc#1173876], unaligned accesses in hybiReadAndDecode     can lead to denial of service

  + LibVNCServer-CVE-2019-20840.patch fix CVE-2020-14398     [bsc#1173880], improperly closed TCP connection causes     an infinite loop in libvncclient/sockets.c

  + LibVNCServer-CVE-2020-14398.patch fix CVE-2020-14397     [bsc#1173700], NULL pointer dereference in     libvncserver/rfbregion.c

  + LibVNCServer-CVE-2020-14397.patch fix CVE-2020-14399     [bsc#1173743], Byte-aligned data is accessed through     uint32_t pointers in libvncclient/rfbproto.c.

  + LibVNCServer-CVE-2020-14399.patch fix CVE-2020-14400     [bsc#1173691], Byte-aligned data is accessed through     uint16_t pointers in libvncserver/translate.c.

  + LibVNCServer-CVE-2020-14400.patch fix CVE-2020-14401     [bsc#1173694], potential integer overflows in     libvncserver/scale.c

  + LibVNCServer-CVE-2020-14401.patch fix CVE-2020-14402     [bsc#1173701], out-of-bounds access via encodings.

  + LibVNCServer-CVE-2020-14402,14403,14404.patch fix     CVE-2017-18922 [bsc#1173477], preauth buffer overwrite

This update was imported from the SUSE:SLE-15:Update update project.

This update for LibVNCServer fixes the following issues :

security update

added patches fix CVE-2018-21247 [bsc#1173874], uninitialized memory contents are vulnerable to Information leak

  + LibVNCServer-CVE-2018-21247.patch fix CVE-2019-20839     [bsc#1173875], buffer overflow in     ConnectClientToUnixSock()

  + LibVNCServer-CVE-2019-20839.patch fix CVE-2019-20840     [bsc#1173876], unaligned accesses in hybiReadAndDecode     can lead to denial of service

  + LibVNCServer-CVE-2019-20840.patch fix CVE-2020-14398     [bsc#1173880], improperly closed TCP connection causes     an infinite loop in libvncclient/sockets.c

  + LibVNCServer-CVE-2020-14398.patch fix CVE-2020-14397     [bsc#1173700], NULL pointer dereference in     libvncserver/rfbregion.c

  + LibVNCServer-CVE-2020-14397.patch fix CVE-2020-14399     [bsc#1173743], Byte-aligned data is accessed through     uint32_t pointers in libvncclient/rfbproto.c.

  + LibVNCServer-CVE-2020-14399.patch fix CVE-2020-14400     [bsc#1173691], Byte-aligned data is accessed through     uint16_t pointers in libvncserver/translate.c.

  + LibVNCServer-CVE-2020-14400.patch fix CVE-2020-14401     [bsc#1173694], potential integer overflows in     libvncserver/scale.c

  + LibVNCServer-CVE-2020-14401.patch fix CVE-2020-14402     [bsc#1173701], out-of-bounds access via encodings.

  + LibVNCServer-CVE-2020-14402,14403,14404.patch fix     CVE-2017-18922 [bsc#1173477], preauth buffer overwrite

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
196364	RHEL 6 : libvncserver (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
150525	SUSE SLES11 Security Update : LibVNCServer (SUSE-SU-2020:14424-1)	Nessus	SuSE Local Security Checks	medium
142357	EulerOS 2.0 SP2 : libvncserver (EulerOS-SA-2020-2362)	Nessus	Huawei Local Security Checks	high
140883	EulerOS 2.0 SP3 : libvncserver (EulerOS-SA-2020-2116)	Nessus	Huawei Local Security Checks	critical
140161	EulerOS 2.0 SP5 : libvncserve (EulerOS-SA-2020-1940)	Nessus	Huawei Local Security Checks	high
139453	SUSE SLES12 Security Update : LibVNCServer (SUSE-SU-2020:2167-1)	Nessus	SuSE Local Security Checks	critical
139141	EulerOS 2.0 SP8 : libvncserver (EulerOS-SA-2020-1811)	Nessus	Huawei Local Security Checks	high
138999	Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : LibVNCServer vulnerabilities (USN-4434-1)	Nessus	Ubuntu Local Security Checks	medium
138984	openSUSE Security Update : LibVNCServer (openSUSE-2020-1056)	Nessus	SuSE Local Security Checks	critical
138828	openSUSE Security Update : LibVNCServer (openSUSE-2020-1025)	Nessus	SuSE Local Security Checks	critical
138751	openSUSE Security Update : LibVNCServer (openSUSE-2020-988)	Nessus	SuSE Local Security Checks	critical
138548	SUSE SLED15 / SLES15 Security Update : LibVNCServer (SUSE-SU-2020:1922-1)	Nessus	SuSE Local Security Checks	critical

Detections

Analytics

CVE-2020-14398

high

Tenable Plugins

critical

medium

high

critical

high

critical

high

medium

critical

critical

critical

critical