package/screen: add security fix for CVE-2021-26937
PATCH 1/1 package/screen: add security fix for CVE-2021-26937
encoding.c in GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.
For more details, see the oss-security discussion:
https://www.openwall.com/lists/oss-security/2021/02/09/3
So far no fix has been added to upstream git, and a number of early proposed fixes caused regressions, so pull the security fix from the screen 4.8.0-5 Debian package.
--- package/screen/0008_CVE-2021-26937.patch | 68 ++++++++++++++++++++++++ package/screen/screen.mk | 3 ++ 2 files changed, 71 insertions(+) create mode 100644 package/screen/0008_CVE-2021-26937.patch
package/screen/0008_CVE-2021-26937.patch new file +68 -0
@@ -0,0 +1,68 @@ +Description: [CVE-2021-26937] Fix out of bounds array access +Author: Michael Schr?der <[email protected]> +Bug-Debian: https://bugs.debian.org/982435 +Bug: https://savannah.gnu.org/bugs/?60030 +Bug: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html +Bug-OSS-Security: https://www.openwall.com/lists/oss-security/2021/02/09/3 +Origin: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00010.html + +Downloaded from Debian: +https://sources.debian.org/data/main/s/screen/4.8.0-5/debian/patches/99_CVE-2021-26937.patch + +Signed-off-by: Peter Korsgaard <[email protected]> +--- a/encoding.c ++++ b/encoding.c +@@ -43,7 +43,7 @@ + # ifdef UTF8 + static int recode_char __P((int, int, int)); + static int recode_char_to_encoding __P((int, int)); +-static void comb_tofront __P((int, int)); ++static void comb_tofront __P((int)); + # ifdef DW_CHARS + static int recode_char_dw __P((int, int *, int, int)); + static int recode_char_dw_to_encoding __P((int, int *, int)); +@@ -1263,6 +1263,8 @@ + {0x30000, 0x3FFFD}, + }; + ++ if (c >= 0xdf00 && c <= 0xdfff) ++ return 1; /* dw combining sequence */ + return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) || + (cjkwidth && + bisearch(c, ambiguous, +@@ -1330,11 +1332,12 @@ + } + + static void +-comb_tofront(root, i) +-int root, i; ++comb_tofront(i) ++int i; + { + for (;;) + { ++ int root = i >= 0x700 ? 0x801 : 0x800; + debug1("bring to front: %x\n", i); + combchars[combchars[i]->prev]->next = combchars[i]->next; + combchars[combchars[i]->next]->prev = combchars[i]->prev; +@@ -1396,9 +1399,9 @@ + { + /* full, recycle old entry */ + if (c1 >= 0xd800 && c1 < 0xe000) +- comb_tofront(root, c1 - 0xd800); ++ comb_tofront(c1 - 0xd800); + i = combchars[root]->prev; +- if (c1 == i + 0xd800) ++ if (i == 0x800 || i == 0x801 || c1 == i + 0xd800) + { + /* completely full, can't recycle */ + debug("utf8_handle_comp: completely full!\n"); +@@ -1422,7 +1425,7 @@ + mc->font = (i >> 8) + 0xd8; + mc->fontx = 0; + debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800); +- comb_tofront(root, i); ++ comb_tofront(i); + } + + #else /* !UTF8 */
package/screen/screen.mk +3 -0
@@ -15,6 +15,9 @@ SCREEN_CONF_ENV = CFLAGS="$(TARGET_CFLAGS)" SCREEN_CONF_OPTS = --enable-colors256 SCREEN_INSTALL_TARGET_OPTS = DESTDIR=$(TARGET_DIR) SCREEN=screen install_bin +# 0008_CVE-2021-26937.patch +SCREEN_IGNORE_CVES += CVE-2021-26937 + ifeq ($(BR2_PACKAGE_LINUX_PAM),y) SCREEN_DEPENDENCIES += linux-pam SCREEN_CONF_OPTS += --enable-pam
Signature · 1 line
2.20.1
Yann E. MORIN
AppliedPATCH 1/1 package/screen: add security fix for CVE-2021-26937
Peter, All,
On 2021-02-27 00:22 +0100, Peter Korsgaard spake thusly:
Quoted 4 lines
encoding.cin GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.
Quoted 8 lines
For more details, see the oss-security discussion:
https://www.openwall.com/lists/oss-security/2021/02/09/3So far no fix has been added to upstream git, and a number of early proposed fixes caused regressions, so pull the security fix from the screen 4.8.0-5 Debian package.
Signed-off-by Peter Korsgaard <[email protected]>
Applied to master, thanks.
Regards,
Yann E. MORIN.
Quoted 101 lines
--- package/screen/0008_CVE-2021-26937.patch | 68 ++++++++++++++++++++++++ package/screen/screen.mk | 3 ++ 2 files changed, 71 insertions(+) create mode 100644 package/screen/0008_CVE-2021-26937.patchpackage/screen/0008_CVE-2021-26937.patch new file +68
-0@@ -0,0 +1,68 @@ +Description: [CVE-2021-26937] Fix out of bounds array access +Author: Michael Schr?der <[email protected]> +Bug-Debian: https://bugs.debian.org/982435 +Bug: https://savannah.gnu.org/bugs/?60030 +Bug: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00000.html +Bug-OSS-Security: https://www.openwall.com/lists/oss-security/2021/02/09/3 +Origin: https://lists.gnu.org/archive/html/screen-devel/2021-02/msg00010.html + +Downloaded from Debian: +https://sources.debian.org/data/main/s/screen/4.8.0-5/debian/patches/99_CVE-2021-26937.patch + +Signed-off-by: Peter Korsgaard <[email protected]> +--- a/encoding.c ++++ b/encoding.c +@@ -43,7 +43,7 @@ + # ifdef UTF8 + static int recode_char __P((int, int, int)); + static int recode_char_to_encoding __P((int, int)); +-static void comb_tofront __P((int, int)); ++static void comb_tofront __P((int)); + # ifdef DW_CHARS + static int recode_char_dw __P((int, int *, int, int)); + static int recode_char_dw_to_encoding __P((int, int *, int)); +@@ -1263,6 +1263,8 @@ + {0x30000, 0x3FFFD}, + }; + ++ if (c >= 0xdf00 && c <= 0xdfff) ++ return 1; /* dw combining sequence */ + return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) || + (cjkwidth && + bisearch(c, ambiguous, +@@ -1330,11 +1332,12 @@ + } + + static void +-comb_tofront(root, i) +-int root, i; ++comb_tofront(i) ++int i; + { + for (;;) + { ++ int root = i >= 0x700 ? 0x801 : 0x800; + debug1("bring to front: %x\n", i); + combchars[combchars[i]->prev]->next = combchars[i]->next; + combchars[combchars[i]->next]->prev = combchars[i]->prev; +@@ -1396,9 +1399,9 @@ + { + /* full, recycle old entry */ + if (c1 >= 0xd800 && c1 < 0xe000) +- comb_tofront(root, c1 - 0xd800); ++ comb_tofront(c1 - 0xd800); + i = combchars[root]->prev; +- if (c1 == i + 0xd800) ++ if (i == 0x800 || i == 0x801 || c1 == i + 0xd800) + { + /* completely full, can't recycle */ + debug("utf8_handle_comp: completely full!\n"); +@@ -1422,7 +1425,7 @@ + mc->font = (i >> 8) + 0xd8; + mc->fontx = 0; + debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800); +- comb_tofront(root, i); ++ comb_tofront(i); + } + + #else /* !UTF8 */package/screen/screen.mk +3
-0@@ -15,6 +15,9 @@ SCREEN_CONF_ENV = CFLAGS="$(TARGET_CFLAGS)" SCREEN_CONF_OPTS = --enable-colors256 SCREEN_INSTALL_TARGET_OPTS = DESTDIR=$(TARGET_DIR) SCREEN=screen install_bin +# 0008_CVE-2021-26937.patch +SCREEN_IGNORE_CVES += CVE-2021-26937 + ifeq ($(BR2_PACKAGE_LINUX_PAM),y) SCREEN_DEPENDENCIES += linux-pam SCREEN_CONF_OPTS += --enable-pamSignature · 6 lines
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Signature · 6 lines
.-----------------.--------------------.------------------.--------------------. | Yann E. MORIN | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: | | +33 662 376 056 | Software Designer | \ / CAMPAIGN | ___ | | +33 561 099 427 `------------.-------: X AGAINST | \e/ There is no | | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL | v conspiracy. | '------------------------------^-------^------------------^--------------------'
PATCH 1/1 package/screen: add security fix for CVE-2021-26937
In reply to Peter KorsgaardQuoted 6 lines
Quoted 1 line
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Quoted 1 line
"Peter" == Peter Korsgaard <[email protected]> writes:
encoding.cin GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.
Quoted 8 lines
For more details, see the oss-security discussion:
https://www.openwall.com/lists/oss-security/2021/02/09/3So far no fix has been added to upstream git, and a number of early proposed fixes caused regressions, so pull the security fix from the screen 4.8.0-5 Debian package.
Signed-off-by Peter Korsgaard <[email protected]>
Committed to 2020.02.x and 2020.11.x, thanks.
Signature · 1 line
Bye, Peter Korsgaard