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.
The product does not conform to the API requirements for a function call that requires extra privileges. This could allow attackers to gain privileges by causing the function to be called incorrectly.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ghostscript | Artifex | 9.00 (including) | 9.50 (excluding) |
| Red Hat Enterprise Linux 7 | RedHat | ghostscript-0:9.25-2.el7_7.3 | * |
| Red Hat Enterprise Linux 8 | RedHat | ghostscript-0:9.25-5.el8_1.1 | * |
| Red Hat Enterprise Linux 8.0 Update Services for SAP Solutions | RedHat | ghostscript-0:9.25-2.el8_0.4 | * |
| Ghostscript | Ubuntu | bionic | * |
| Ghostscript | Ubuntu | devel | * |
| Ghostscript | Ubuntu | disco | * |
| Ghostscript | Ubuntu | eoan | * |
| Ghostscript | Ubuntu | trusty | * |
| Ghostscript | Ubuntu | xenial | * |
When a product contains certain functions that perform operations requiring an elevated level of privilege, the caller of a privileged API must be careful to:
If the caller of the API does not follow these requirements, then it may allow a malicious user or process to elevate their privilege, hijack the process, or steal sensitive data. For instance, it is important to know if privileged APIs do not shed their privileges before returning to the caller or if the privileged function might make certain assumptions about the data, context or state information passed to it by the caller. It is important to always know when and how privileged APIs can be called in order to ensure that their elevated level of privilege cannot be exploited.