Integer overflow in the MallocFrameBuffer function in vncviewer.c in L ...
Last updated 24 July 2024
Last updated 24 July 2024
Last updated 24 July 2024
Two stack-based buffer overflow flaws were reported in LibVNCServer's file transfer handling. A VNC client could use these flaws to cause the VNC server to crash or, potentially, execute arbitrary code.
Upstream commits:
https://github.com/newsoft/libvncserver/commit/06ccdf016154fde8eccb5355613ba04c59127b2e
https://github.com/newsoft/libvncserver/commit/f528072216dec01cee7ca35d94e171a3b909e677
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)
It was discovered that LibVNCServer incorrectly handled decompressing data. An attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. (CVE-2019-15680) It was discovered that an information disclosure vulnerability existed in LibVNCServer when sending a ServerCutText message. An attacker could possibly use this issue to expose sensitive information. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS. (CVE-2019-15681) It was discovered that LibVNCServer incorrectly handled cursor shape updates. If a user were tricked in to connecting to a malicious server, an attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS. (CVE-2019-15690, CVE-2019-20788) It was discovered that LibVNCServer incorrectly handled decoding WebSocket frames. An attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS. (CVE-2017-18922)
It was discovered that LibVNCServer incorrectly handled certain operations. A remote attacker able to connect to applications using LibVNCServer could possibly use this issue to obtain sensitive information, cause a denial of service, or execute arbitrary code.
Nicolas Ruff discovered that LibVNCServer incorrectly handled memory when being advertised large screen sizes by the server. If a user were tricked into connecting to a malicious server, an attacker could use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2014-6051, CVE-2014-6052) Nicolas Ruff discovered that LibVNCServer incorrectly handled large ClientCutText messages. A remote attacker could use this issue to cause a server to crash, resulting in a denial of service. (CVE-2014-6053) Nicolas Ruff discovered that LibVNCServer incorrectly handled zero scaling factor values. A remote attacker could use this issue to cause a server to crash, resulting in a denial of service. (CVE-2014-6054) Nicolas Ruff discovered that LibVNCServer incorrectly handled memory in the file transfer feature. A remote attacker could use this issue to cause a server to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2014-6055)