CVE-2017-18206

In utils.c in zsh before 5.4, symlink expansion had a buffer overflow.

Zsh has been updated to fix 4 security issues.

In builtin.c in zsh before 5.4, when sh compatibility mode is used, there is a NULL pointer dereference during processing of the cd command with no argument if HOME is not set. (CVE-2017-18205)

In utils.c in zsh before 5.4, symlink expansion had a buffer overflow. (CVE-2017-18206)

In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.(CVE-2018-7548)

In params.c in zsh through 5.4.2, there is a crash during a copy of an empty hash table, as demonstrated by typeset -p. (CVE-2018-7549)

This update for zsh fixes the following issues:

• CVE-2014-10070: environment variable injection could lead to local privilege escalation (bnc#1082885)

• CVE-2014-10071: buffer overflow in exec.c could lead to denial of service. (bnc#1082977)

• CVE-2014-10072: buffer overflow In utils.c when scanning very long directory paths for symbolic links. (bnc#1082975)

• CVE-2016-10714: In zsh before 5.3, an off-by-one error resulted in undersized buffers that were intended to support PATH_MAX characters. (bnc#1083250)

• CVE-2017-18205: In builtin.c when sh compatibility mode is used, a NULL pointer dereference could lead to denial of service (bnc#1082998)

• CVE-2018-1071: exec.c:hashcmd() function vulnerability could lead to denial of service. (bnc#1084656)

• CVE-2018-1083: Autocomplete vulnerability could lead to privilege escalation. (bnc#1087026)

• CVE-2018-7549: In params.c in zsh through 5.4.2, there is a crash during a copy of an empty hash table, as demonstrated by typeset -p. (bnc#1082991)

• CVE-2017-18206: buffer overrun in xsymlinks could lead to denial of service (bnc#1083002)

• Autocomplete and REPORTTIME broken (bsc#896914)

This update for zsh fixes the following issues:

• CVE-2019-20044: Fixed an insecure dropping of privileges when unsetting the PRIVILEGED option (bsc#1163882).
• CVE-2018-13259: Fixed an unexpected truncation of long shebang lines (bsc#1107294).
• CVE-2018-7549: Fixed a crash when an empty hash table (bsc#1082991).
• CVE-2018-1083: Fixed a stack-based buffer overflow when using tab completion on directories with long names (bsc#1087026).
• CVE-2018-1071: Fixed a stack-based buffer overflow when executing certain commands (bsc#1084656).
• CVE-2018-0502: Fixed a mishandling of shebang lines (bsc#1107296).
• CVE-2017-18206: Fixed a buffer overflow related to symlink processing (bsc#1083002).
• CVE-2017-18205: Fixed an application crash when using cd with no arguments (bsc#1082998).
• CVE-2016-10714: Fixed a potential application crash when handling maximum length paths (bsc#1083250).
• CVE-2014-10072: Fixed a buffer overflow when scanning very long directory paths for symbolic links (bsc#1082975).
• CVE-2014-10071: Fixed a buffer overflow when redirecting output to a long file descriptor (bsc#1082977).
• CVE-2014-10070: Fixed a privilege escalation vulnerability via environment variables (bsc#1082885).

It was discovered that Zsh incorrectly handled certain enviroment variables. An attacker could possibly use this issue to gain privileged access to the system. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10070)

It was discovered that Zsh incorrectly handled certain inputs. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10071)

It was discovered that Zsh incorrectly handled some symbolic links. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 14.04 LTS. (CVE-2014-10072)

It was discovered that Zsh incorrectly handled certain errors. An attacker could possibly use this issue to cause a denial of service. (CVE-2016-10714)

It was discovered that Zsh incorrectly handled certain commands. An attacker could possibly use this to execute arbitrary code. (CVE-2017-18205)

It was discovered that Zsh incorrectly handled certain symlinks. An attacker could possibly use this to execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 17.10. (CVE-2017-18206)

It was discovered that Zsh incorrectly handled certain inputs. An attacker could possible use to execute arbitrary code. This issue only affected Ubuntu 17.10. (CVE-2018-7548)

It was discovered that Zsh incorrectly handled certain inputs. An attacker could possibly use this to cause a denial of service. (CVE-2018-7549)