Debian: >> Debian Linux Security Vulnerabilities
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to cause a denial of service via a VCPUOP_initialise hypercall. hypercall_create_continuation() is a variadic function which uses a printf-like format string to interpret its parameters. Error handling for a bad format character was done using BUG(), which crashes Xen. One path, via the VCPUOP_initialise hypercall, has a bad format character. The BUG() can be hit if VCPUOP_initialise executes for a sufficiently long period of time for a continuation to be created. Malicious guests may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen versions 4.6 and newer are vulnerable. Xen versions 4.5 and earlier are not vulnerable. Only x86 PV guests can exploit the vulnerability. HVM and PVH guests, and guests on ARM systems, cannot exploit the vulnerability.
CVSS Score
6.5
EPSS Score
0.04
Published
2019-10-31
An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations. There are issues with restartable PV type change operations. To avoid using shadow pagetables for PV guests, Xen exposes the actual hardware pagetables to the guest. In order to prevent the guest from modifying these page tables directly, Xen keeps track of how pages are used using a type system; pages must be "promoted" before being used as a pagetable, and "demoted" before being used for any other type. Xen also allows for "recursive" promotions: i.e., an operating system promoting a page to an L4 pagetable may end up causing pages to be promoted to L3s, which may in turn cause pages to be promoted to L2s, and so on. These operations may take an arbitrarily large amount of time, and so must be re-startable. Unfortunately, making recursive pagetable promotion and demotion operations restartable is incredibly complicated, and the code contains several races which, if triggered, can cause Xen to drop or retain extra type counts, potentially allowing guests to get write access to in-use pagetables. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All x86 systems with untrusted PV guests are vulnerable. HVM and PVH guests cannot exercise this vulnerability.
CVSS Score
7.5
EPSS Score
0.019
Published
2019-10-31
An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service or gain privileges by leveraging the erroneous enabling of interrupts. Interrupts are unconditionally unmasked in exception handlers. When an exception occurs on an ARM system which is handled without changing processor level, some interrupts are unconditionally enabled during exception entry. So exceptions which occur when interrupts are masked will effectively unmask the interrupts. A malicious guest might contrive to arrange for critical Xen code to run with interrupts erroneously enabled. This could lead to data corruption, denial of service, or possibly even privilege escalation. However a precise attack technique has not been identified.
CVSS Score
8.8
EPSS Score
0.035
Published
2019-10-31
Transmission before 1.92 allows an attacker to cause a denial of service (crash) or possibly have other unspecified impact via a large number of tr arguments in a magnet link.
CVSS Score
9.8
EPSS Score
0.009
Published
2019-10-30
Transmission before 1.92 allows attackers to prevent download of a file by corrupted data during the endgame.
CVSS Score
5.3
EPSS Score
0.007
Published
2019-10-30
drbd8 allows local users to bypass intended restrictions for certain actions via netlink packets, similar to CVE-2009-3725.
CVSS Score
7.8
EPSS Score
0.0
Published
2019-10-30
xpdf allows remote attackers to cause a denial of service (NULL pointer dereference and crash) in the way it processes JBIG2 PDF stream objects.
CVSS Score
5.5
EPSS Score
0.004
Published
2019-10-30
In xpdf, the xref table contains an infinite loop which allows remote attackers to cause a denial of service (application crash) in xpdf-based PDF viewers.
CVSS Score
5.5
EPSS Score
0.004
Published
2019-10-30
The Debian backport of the fix for CVE-2017-3137 leads to assertion failure in validator.c:1858; Affects Debian versions 9.9.5.dfsg-9+deb8u15; 9.9.5.dfsg-9+deb8u18; 9.10.3.dfsg.P4-12.3+deb9u5; 9.11.5.P4+dfsg-5.1 No ISC releases are affected. Other packages from other distributions who did similar backports for the fix for 2017-3137 may also be affected.
CVSS Score
7.5
EPSS Score
0.006
Published
2019-10-30
ikiwiki before 3.20110608 allows remote attackers to hijack root's tty and run symlink attacks.
CVSS Score
8.2
EPSS Score
0.006
Published
2019-10-29