CVE-2020-24240

GNU Bison before 3.7.1 has a use-after-free in obstackfree in lib/obstack.c called from gramlex when a '\0' byte is encountered. NOTE: there is a risk only if Bison is used with untrusted input, and the observed bug happens to cause unsafe behavior with a specific compiler/architecture. The bug...

CVE-2020-24240

CVE-2020-24240 concerns GNU Bison before 3.7.1, which contains a use-after-free in _obstack_free (lib/obstack.c) when a NULL byte is encountered during gram_lex. The risk is limited to cases where Bison processes untrusted input, and the observed behavior was primarily a crash in Bison itself, no...

Use After Free

GNU Bison has a use-after-free in obstackfree in lib/obstack.c called from gramlex when a '\0' byte is encountered. NOTE: there is a risk only if Bison is used with untrusted input, and the observed bug happens to cause unsafe behavior with a specific compiler/architecture. The bug report was...

SecGen - Create Randomly Insecure VMs

SecGen creates vulnerable virtual machines, lab environments, and hacking challenges, so students can learn security penetration testing techniques. Boxes like Metasploitable2 are always the same, this project uses Vagrant, Puppet, and Ruby to create randomly vulnerable virtual machines that can ...

In GNU patch through 2.7.6 the following of symlinks is mishandled in certain cases other than input files. This affects inp.c and util.c.

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A use-after-free vulnerability introduced in glibc upstream version 2.14 was found in the way the tilde expansion was carried out. Directory paths containing an initial tilde followed by a valid username were affected by this issue. A local attacker could exploit this flaw by creating a specially crafted path that when processed by the glob function would potentially lead to arbitrary code execution. This was fixed in version 2.32.

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An issue was discovered in GNU libiberty as distributed in GNU Binutils 2.32. simple_object_elf_match in simple-object-elf.c does not check for a zero shstrndx value leading to an integer overflow and resultant heap-based buffer overflow.

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An issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11. By default if Bash is run with its effective UID not equal to its real UID it will drop privileges by setting its effective UID to its real UID. However it does so incorrectly. On Linux and other systems that support "saved UID" functionality the saved UID is not dropped. An attacker with command execution in the shell can use "enable -f" for runtime loading of a new builtin which can be a shared object that calls setuid() and therefore regains privileges. However binaries running with an effective UID of 0 are unaffected.

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An issue was discovered in the Binary File Descriptor (BFD) library (aka libbfd) as distributed in GNU Binutils 2.32. It is an integer overflow leading to a SEGV in _bfd_dwarf2_find_nearest_line in dwarf2.c as demonstrated by nm.

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do_ed_script in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character. NOTE: this is the same commit as for CVE-2019-13638 but the ! syntax is specific to ed and is unrelated to a shell metacharacter.

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The GNU C Library (aka glibc or libc6) before 2.32 could overflow an on-stack buffer during range reduction if an input to an 80-bit long double function contains a non-canonical bit pattern a seen when passing a 0x5d414141414141410000 value to sinl on x86 targets. This is related to sysdeps/ieee754/ldbl-96/e_rem_pio2l.c.

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In the GNU C Library (aka glibc or libc6) through 2.28 attempting to resolve a crafted hostname via getaddrinfo() leads to the allocation of a socket descriptor that is not closed. This is related to the if_nametoindex() function.

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In the GNU C Library (aka glibc or libc6) through 2.29 proceed_next_node in posix/regexec.c has a heap-based buffer over-read via an attempted case-insensitive regular-expression match.

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In the GNU C Library (aka glibc or libc6) through 2.28 the getaddrinfo function would successfully parse a string that contained an IPv4 address followed by whitespace and arbitrary characters which could lead applications to incorrectly assume that it had parsed a valid string without the possibility of embedded HTTP headers or other potentially dangerous substrings.

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An issue was discovered in GNU patch through 2.7.6. There is a segmentation fault associated with a NULL pointer dereference leading to a denial of service in the intuit_diff_type function in pch.c aka a "mangled rename" issue.

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An issue was discovered in GNU Binutils 2.32. It is a heap-based buffer overflow in process_mips_specific in readelf.c via a malformed MIPS option section.

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In the GNU C Library (aka glibc or libc6) through 2.29 check_dst_limits_calc_pos_1 in posix/regexec.c has Uncontrolled Recursion as demonstrated by '(\227|)(\\1\\1|t1|\\\2537)+' in grep.

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An issue was discovered in GNU libiberty as distributed in GNU Binutils 2.32. It is a stack consumption issue in d_count_templates_scopes in cp-demangle.c after many recursive calls.

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The POWER9 backend in GNU Compiler Collection (GCC) before version 10 could optimize multiple calls of the __builtin_darn intrinsic into a single call thus reducing the entropy of the random number generator. This occurred because a volatile operation was not specified. For example within a single execution of a program the output of every __builtin_darn() call may be the same.

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GNU Patch version 2.7.6 contains an input validation vulnerability when processing patch files, specifically the EDITOR_PROGRAM invocation (using ed) can result in code execution. This attack appear to be exploitable via a patch file processed via the patch utility. This is similar to FreeBSD's CVE-2015-1418 however although they share a common ancestry the code bases have diverged over time.

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