diff --git a/ksh-2020.0.0-cve-2019-14868.patch b/ksh-2020.0.0-cve-2019-14868.patch new file mode 100644 index 0000000..b8ff83c --- /dev/null +++ b/ksh-2020.0.0-cve-2019-14868.patch @@ -0,0 +1,78 @@ +diff --git a/src/cmd/ksh93/sh/arith.c b/src/cmd/ksh93/sh/arith.c +--- a/src/cmd/ksh93/sh/arith.c ++++ b/src/cmd/ksh93/sh/arith.c +@@ -567,19 +567,32 @@ Sfdouble_t sh_strnum(Shell_t *shp, const char *str, char **ptr, int mode) { + char *last; + + if (*str == 0) { +- if (ptr) *ptr = (char *)str; +- return 0; +- } +- errno = 0; +- d = number(str, &last, shp->inarith ? 0 : 10, NULL); +- if (*last) { +- if (*last != '.' || last[1] != '.') { +- d = strval(shp, str, &last, arith, mode); +- Varsubscript = true; ++ d = 0.0; ++ last = (char *)str; ++ } else { ++ d = number(str, &last, shp->inarith ? 0 : 10, NULL); ++ if (*last && !shp->inarith && sh_isstate(shp, SH_INIT)) { ++ // This call is to handle "base#value" literals if we're importing untrusted env vars. ++ d = number(str, &last, 0, NULL); ++ } ++ if (*last) { ++ if (sh_isstate(shp, SH_INIT)) { ++ // Initializing means importing untrusted env vars. Since the string does not appear ++ // to be a recognized numeric literal give up. We can't safely call strval() since ++ // that allows arbitrary expressions which would create a security vulnerability. ++ d = 0.0; ++ } else { ++ if (*last != '.' || last[1] != '.') { ++ d = strval(shp, str, &last, arith, mode); ++ Varsubscript = true; ++ } ++ if (!ptr && *last && mode > 0) { ++ errormsg(SH_DICT, ERROR_exit(1), e_lexbadchar, *last, str); ++ } ++ } ++ } else if (d == 0.0 && *str == '-') { ++ d = -0.0; + } +- if (!ptr && *last && mode > 0) errormsg(SH_DICT, ERROR_exit(1), e_lexbadchar, *last, str); +- } else if (!d && *str == '-') { +- d = -0.0; + } + if (ptr) *ptr = last; + return d; +diff --git a/src/cmd/ksh93/tests/subshell.sh b/src/cmd/ksh93/tests/subshell.sh +--- a/src/cmd/ksh93/tests/subshell.sh ++++ b/src/cmd/ksh93/tests/subshell.sh +@@ -856,3 +856,26 @@ for exp in 65535 65536 + do got=$($SHELL -c 'x=$(printf "%.*c" '$exp' x); print ${#x}' 2>&1) + [[ $got == $exp ]] || log_error "large command substitution failed" "$exp" "$got" + done ++ ++# ========== ++# Verify that importing untrusted env vars does not allow evaluating arbitrary expressions but does ++# recognize all integer literals recognized by ksh. ++expect=8 ++actual=$(env SHLVL='7' $SHELL -c 'echo $SHLVL') ++[[ $actual == $expect ]] || log_error "decimal int literal not recognized" "$expect" "$actual" ++ ++expect=14 ++actual=$(env SHLVL='013' $SHELL -c 'echo $SHLVL') ++[[ $actual == $expect ]] || log_error "leading zeros int literal not recognized" "$expect" "$actual" ++ ++expect=4 ++actual=$(env SHLVL='2#11' $SHELL -c 'echo $SHLVL') ++[[ $actual == $expect ]] || log_error "base#value int literal not recognized" "$expect" "$actual" ++ ++expect=12 ++actual=$(env SHLVL='16#B' $SHELL -c 'echo $SHLVL') ++[[ $actual == $expect ]] || log_error "base#value int literal not recognized" "$expect" "$actual" ++ ++expect=1 ++actual=$(env SHLVL="2#11+x[\$($bin_echo DANGER WILL ROBINSON >&2)0]" $SHELL -c 'echo $SHLVL') ++[[ $actual == $expect ]] || log_error "expression allowed on env var import" "$expect" "$actual" diff --git a/ksh.spec b/ksh.spec index d972711..52a55bf 100644 --- a/ksh.spec +++ b/ksh.spec @@ -3,7 +3,7 @@ Summary: The Original ATT Korn Shell URL: http://www.kornshell.com/ License: EPL Version: 2020.0.0 -Release: 2%{?dist} +Release: 3%{?dist} # We are upgrading from ksh-20120801-250, so set epoch. Epoch: 1 Source0: https://github.com/att/ast/releases/download/%{version}/%{name}-%{version}.tar.gz @@ -11,6 +11,8 @@ Source1: kshcomp.conf Source2: kshrc.rhs Source3: dotkshrc +Patch1: ksh-2020.0.0-cve-2019-14868.patch + Provides: /bin/ksh BuildRequires: meson @@ -32,7 +34,7 @@ KornShell is a shell programming language, which is upward compatible with "sh" (the Bourne Shell). %prep -%autosetup -n %{name}-%{version} +%autosetup -n %{name}-%{version} -p1 %build %meson -Dbuild-api-tests=false @@ -108,6 +110,10 @@ done %config(noreplace) %{_sysconfdir}/binfmt.d/kshcomp.conf %changelog +* Fri Feb 07 2020 Siteshwar Vashisht - 1:2020.0.0-3 +- Do not evaluate arithmetic expressions from environment variables at startup + Resolves: #1790549 + * Wed Jan 29 2020 Fedora Release Engineering - 1:2020.0.0-2 - Rebuilt for https://fedoraproject.org/wiki/Fedora_32_Mass_Rebuild