Artifex Ghostscript

A trivial sandbox (enabled with the `-dSAFER` option) escape flaw was found in the ghostscript interpreter by injecting a specially crafted pipe command. This flaw allows a specially crafted document to execute arbitrary commands on the system in the context of the ghostscript interpreter. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

A flaw was found in ghostscript, versions 9.x before 9.50, in the setsystemparams procedure where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. A specially crafted PostScript file could disable security protection and then have access to the file system, or execute arbitrary commands.

An issue was discovered in Artifex Ghostscript before 9.26. LockSafetyParams is not checked correctly if another device is used.

Ghostscript before 9.21 might allow remote attackers to bypass the SAFER mode protection mechanism and consequently execute arbitrary code by leveraging type confusion in .initialize_dsc_parser.

In Artifex Ghostscript through 10.01.0, there is a buffer overflow leading to potential corruption of data internal to the PostScript interpreter, in base/sbcp.c. This affects BCPEncode, BCPDecode, TBCPEncode, and TBCPDecode. If the write buffer is filled to one byte less than full, and one then tries to write an escaped character, two bytes are written.

Use-after-free vulnerability in Ghostscript 9.20 might allow remote attackers to execute arbitrary code via vectors related to a reference leak in .setdevice.

A memory corruption issue was found in Artifex Ghostscript 9.50 and 9.52. Use of a non-standard PostScript operator can allow overriding of file access controls. The 'rsearch' calculation for the 'post' size resulted in a size that was too large, and could underflow to max uint32_t. This was fixed in commit 5d499272b95a6b890a1397e11d20937de000d31b.

Artifex Ghostscript before 9.53.0 has an out-of-bounds write and use-after-free in devices/vector/gdevtxtw.c (for txtwrite) because a single character code in a PDF document can map to more than one Unicode code point (e.g., for a ligature).

An issue was discovered in Artifex Ghostscript before 10.05.0. The NPDL device has a Compression buffer overflow for contrib/japanese/gdevnpdl.c.

An issue was discovered in Artifex Ghostscript before 10.05.0. Access to arbitrary files can occur through a truncated path with invalid UTF-8 characters, for base/gp_mswin.c and base/winrtsup.cpp.

An issue was discovered in Artifex Ghostscript before 10.05.0. The BJ10V device has a Print buffer overflow in contrib/japanese/gdev10v.c.

An issue was discovered in Artifex Ghostscript before 10.05.0. The DOCXWRITE TXTWRITE device has a text buffer overflow via long characters to devices/vector/doc_common.c.

An issue was discovered in Artifex Ghostscript before 9.24. Incorrect "restoration of privilege" checking during handling of /invalidaccess exceptions could be used by attackers able to supply crafted PostScript to execute code using the "pipe" instruction.

It was found that RHSA-2018:2918 did not fully fix CVE-2018-16509. An attacker could possibly exploit another variant of the flaw and bypass the -dSAFER protection to, for example, execute arbitrary shell commands via a specially crafted PostScript document. This only affects ghostscript 9.07 as shipped with Red Hat Enterprise Linux 7.

The PS Interpreter in Ghostscript 9.18 and 9.20 allows remote attackers to execute arbitrary code via crafted userparams.

In Artifex Ghostscript through 10.01.2, gdevijs.c in GhostPDL can lead to remote code execution via crafted PostScript documents because they can switch to the IJS device, or change the IjsServer parameter, after SAFER has been activated. NOTE: it is a documented risk that the IJS server can be specified on a gs command line (the IJS device inherently must execute a command to start the IJS server).

A flaw was found in all versions of ghostscript 9.x before 9.50, where the `.charkeys` procedure, where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. An attacker could abuse this flaw by creating a specially crafted PostScript file that could escalate privileges within the Ghostscript and access files outside of restricted areas or execute commands.

Artifex Ghostscript before 10.03.0 has a heap-based overflow when PDFPassword (e.g., for runpdf) has a \000 byte in the middle.

An issue was discovered in Artifex Ghostscript before 10.03.1. contrib/opvp/gdevopvp.c allows arbitrary code execution via a custom Driver library, exploitable via a crafted PostScript document. This occurs because the Driver parameter for opvp (and oprp) devices can have an arbitrary name for a dynamic library; this library is then loaded.

Artifex Ghostscript before 10.03.0 has a stack-based buffer overflow in the pdfi_apply_filter() function via a long PDF filter name.

Artifex Ghostscript 9.25 and earlier allows attackers to bypass a sandbox protection mechanism via vectors involving the 1Policy operator.

Artifex Ghostscript 9.25 and earlier allows attackers to bypass a sandbox protection mechanism via vectors involving errorhandler setup. NOTE: this issue exists because of an incomplete fix for CVE-2018-17183.

An issue was discovered in decode_utf8 in base/gp_utf8.c in Artifex Ghostscript before 10.04.0. Overlong UTF-8 encoding leads to possible ../ directory traversal.

An issue was discovered in pdf/pdf_xref.c in Artifex Ghostscript before 10.04.0. There is a buffer overflow during handling of a PDF XRef stream (related to W array values).

Artifex Ghostscript through 2017-04-26 allows -dSAFER bypass and remote command execution via .rsdparams type confusion with a "/OutputFile (%pipe%" substring in a crafted .eps document that is an input to the gs program, as exploited in the wild in April 2017.

In Artifex Ghostscript through 9.26, ephemeral or transient procedures can allow access to system operators, leading to remote code execution.

psi/zdevice2.c in Artifex Ghostscript before 9.26 allows remote attackers to bypass intended access restrictions because available stack space is not checked when the device remains the same.

Artifex Ghostscript through 10.01.2 mishandles permission validation for pipe devices (with the %pipe% prefix or the | pipe character prefix).

A flaw was found in, ghostscript versions prior to 9.50, in the .pdf_hook_DSC_Creator procedure where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. A specially crafted PostScript file could disable security protection and then have access to the file system, or execute arbitrary commands.

The .sethalftone5 function in psi/zht2.c in Ghostscript before 9.21 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted Postscript document that calls .sethalftone5 with an empty operand stack.

psi/zicc.c in Artifex Ghostscript before 9.26 allows remote attackers to bypass intended access restrictions because of a setcolorspace type confusion.

psi/zfjbig2.c in Artifex Ghostscript before 9.26 allows remote attackers to bypass intended access restrictions because of a JBIG2Decode type confusion.

In Artifex Ghostscript before 9.24, attackers able to supply crafted PostScript files could use a type confusion in the LockDistillerParams parameter to crash the interpreter or execute code.

In Artifex Ghostscript 9.23 before 2018-08-24, attackers able to supply crafted PostScript could use uninitialized memory access in the aesdecode operator to crash the interpreter or potentially execute code.

In Artifex Ghostscript 9.23 before 2018-08-24, a type confusion using the .shfill operator could be used by attackers able to supply crafted PostScript files to crash the interpreter or potentially execute code.

In Artifex Ghostscript through 9.25, the setpattern operator did not properly validate certain types. A specially crafted PostScript document could exploit this to crash Ghostscript or, possibly, execute arbitrary code in the context of the Ghostscript process. This is a type confusion issue because of failure to check whether the Implementation of a pattern dictionary was a structure type.

The gs_alloc_ref_array function in psi/ialloc.c in Artifex Ghostscript 9.21 allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted PostScript document. This is related to a lack of an integer overflow check in base/gsalloc.c.

A flaw was found in all ghostscript versions 9.x before 9.50, in the .setuserparams2 procedure where it did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. A specially crafted PostScript file could disable security protection and then have access to the file system, or execute arbitrary commands.

psi/ztoken.c in Artifex Ghostscript 9.21 mishandles references to the scanner state structure, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted PostScript document, related to an out-of-bounds read in the igc_reloc_struct_ptr function in psi/igc.c.

In ghostscript before version 9.50, the .buildfont1 procedure did not properly secure its privileged calls, enabling scripts to bypass `-dSAFER` restrictions. An attacker could abuse this flaw by creating a specially crafted PostScript file that could escalate privileges and access files outside of restricted areas.